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Author name code: bettonvil
ADS astronomy entries on 2022-09-14
author:"Bettonvil, Felix C.M."
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Title: Locating dust and molecules in the inner circumstellar
environment of R~Sculptoris with MATISSE
Authors: Drevon, Julien; Millour, Florentin; Cruzalèbes, Pierre;
Paladini, Claudia; Hron, Josef; Meilland, A.; Allouche, F.; Hofmann,
K. -H.; Lagarde, S.; Lopez, B.; Matter, A.; Petrov, R.; Robbe-Dubois,
S.; Schertl, D.; Wittkowski, M.; Zins, G.; Ábrahám, P.; Antonelli,
P.; Beckmann, U.; Berio, P.; Bettonvil, F.; Glindemann, A.; Graser,
U.; Heininger, M.; Henning, Thomas; Isbell, Jacob W.; Jaffe,
Walter; Labadie, Lucas; Leinert, Christoph; Lehmitz, Michael;
Morel, Sébastien; Meisenheimer, Klaus; Soulain, Anthony; Varga,
Josef; Weigelt, Gerd; Woillez, Julien; Augereau, Jean-Charles; van
Boekel, Roy; Burtscher, Leonard; Danchi, William; Dominik, Carsten;
Gamez-Rosas, Violetta; Hocdé, Vincent; Hogerheijde, M.; Klarmann,
Lucia; Kokoulina, Elena; Leftley, James; Stee, Ph.; Vakili, Farrokh;
Waters, Rens; Wolf, Sebastian; Yoffe, Gideon
2022arXiv220810845D Altcode:
AGB stars are one of the main sources of dust production in the
Galaxy. However, it is not clear what this process looks like and
where the dust is condensing in the circumstellar environment. By
characterizing the location of the dust and the molecules in the close
environment of an AGB star, we aim to achieve a better understanding
the history of the dust formation process. We observed the carbon star
R Scl with the VLTI-MATISSE instrument in L- and N-bands. The high
angular resolution of the VLTI observations, combined with a large
uv-plane coverage allowed us to use image reconstruction methods. To
constrain the dust and molecules' location, we used two different
methods: MIRA image reconstruction and the 1D code RHAPSODY. We found
evidence of C2H2 and HCN molecules between 1 and 3.4 Rstar which is
much closer to the star than the location of the dust (between 3.8
and 17.0 Rstar). We also estimated a mass-loss rate of 1.2+-0.4x10-6
Msun per yr. In the meantime, we confirmed the previously published
characteristics of a thin dust shell, composed of amorphous carbon
(amC) and silicon carbide (SiC). However, no clear SiC feature has
been detected in the MATISSE visibilities. This might be caused by
molecular absorption that can affect the shape of the SiC band at 11.3
micron. The appearance of the molecular shells is in good agreement
with predictions from dynamical atmosphere models. For the first time,
we co-located dust and molecules in the environment of an AGB star. We
confirm that the molecules are located closer to the star than the
dust. The MIRA images unveil the presence of a clumpy environment in the
fuzzy emission region beyond 4.0 Rstar. Furthermore, with the available
dynamic range and angular resolution, we did not detect the presence
of a binary companion. Additional observations combining MATISSE and
SAM-VISIR instrument should enable this detection in future studies.
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Title: The dusty heart of Circinus. I. Imaging the circumnuclear
dust in N-band
Authors: Isbell, J. W.; Meisenheimer, K.; Pott, J. -U.; Stalevski,
M.; Tristram, K. R. W.; Sanchez-Bermudez, J.; Hofmann, K. -H.; Gámez
Rosas, V.; Jaffe, W.; Burtscher, L.; Leftley, J.; Petrov, R.; Lopez,
B.; Henning, T.; Weigelt, G.; Allouche, F.; Berio, P.; Bettonvil, F.;
Cruzalebes, P.; Dominik, C.; Heininger, M.; Hogerheijde, M.; Lagarde,
S.; Lehmitz, M.; Matter, A.; Meilland, A.; Millour, F.; Robbe-Dubois,
S.; Schertl, D.; van Boekel, R.; Varga, J.; Woillez, J.
2022A&A...663A..35I Altcode: 2022arXiv220501575I
Context. Active galactic nuclei play a key role in the evolution of
galaxies, but their inner workings and physical connection to the host
are poorly understood due to a lack of angular resolution. Infrared
interferometry makes it possible to resolve the circumnuclear
dust in the nearby Seyfert 2 galaxy, the Circinus Galaxy. Previous
observations have revealed complex structures and polar dust emission
but interpretation was limited to simple models. The new Multi AperTure
mid-Infrared Spectro-Scopic Experiment (MATISSE) makes it possible
to image these structures for the first time. <BR /> Aims: We aim to
precisely map the morphology and temperature of the dust surrounding
the supermassive black hole through interferometric imaging. <BR />
Methods: We observed the Circinus Galaxy with MATISSE at the Very
Large Telescope Interferometer (VLTI), producing 150 correlated flux
spectra and 100 closure phase spectra. The novel inclusion of closure
phases makes interferometric imaging possible for the first time. We
reconstructed images in the N-band at ∼10 mas resolution. We fit
blackbody functions with dust extinction to several aperture-extracted
fluxes from the images to produce a temperature distribution of central
dusty structures. <BR /> Results: We find significant substructure
in the circumnuclear dust: central unresolved flux of ∼0.5 Jy,
a thin disk 1.9 pc in diameter oriented along ∼45°, and a ∼4
× 1.5 pc polar emission extending orthogonal to the disk. The polar
emission exhibits patchiness, which we attribute to clumpy dust. Flux
enhancements to the east and west of the disk are seen for the first
time. We distinguish the temperature profiles of the disk and of the
polar emission: the disk shows a steep temperature gradient indicative
of denser material; the polar profile is flatter, indicating clumpiness
and/or lower dust density. The unresolved flux is fitted with a high
temperature, ∼370 K. The polar dust remains warm (∼200 K) out
to 1.5 pc from the disk. We attribute approximately 60% of the 12
μm flux to the polar dust, 10% to the disk, and 6% is unresolved;
the remaining flux was resolved out. The recovered morphology and
temperature distribution resembles modeling of accretion disks with
radiation-driven winds at large scales, but we placed new constraints on
the subparsec dust. <BR /> Conclusions: The spatially resolved subparsec
features imaged here place new constraints on the physical modeling
of circumnuclear dust in active galaxies; we show strong evidence that
the polar emission consists of dust clumps or filaments. The dynamics
of the structures and their role in the Unified Model remain to be
explored. <P />This work makes use of ESO Programmes 099.B-0484(A),
0104.B-0064(A), 0104.B-0127(A), 106.214U.002, and 105.205M.001. <P
/>The images in Fig. 3 are available at the CDS via anonymous ftp to
<A href="http://cdsarc.u-strasbg.fr/">cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/663/A35">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/663/A35</A>
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Title: VizieR Online Data Catalog: Circinus galaxy N-band VLTI/MATISSE
images (Isbell+, 2022)
Authors: Isbell, J. W.; Meisenheimer, K.; Pott, J. -U.; Stalevski,
M.; Tristram, K. R. W.; Sanchez-Bermudez, J.; Hofmann, K. -H.; Gamez
Rosas, V.; Jaffe, W.; Burtscher, L.; Leftley, J.; Petrov, R.; Lopez,
B.; Henning, T.; Weigelt, G.; Allouche, F.; Berio, P.; Bettonvil, F.;
Cruzalebes, P.; Dominik, C.; Heininger, M.; Hogerheijde, M.; Lagarde,
S.; Lehmitz, M.; Matter, A.; Meilland, A.; Millour, F.; Robbe-Dubois,
S.; Schertl, D.; van Boekel, R.; Varga, J.; Woillez, J.
2022yCat..36630035I Altcode:
Observations of the active galactic nucleus (AGN), Circinus, with
VLTI/MATISSE resulted in the reconstruction of images at seven
independent wavelength channels in the N-band. These images show
the circumnuclear dust and provide new details on constraints on the
structure commonly known as the AGN torus. The images were reconstructed
from 150 correlated flux and 100 closure phase measurements obtained in
March 2020, February 2021, and June 2021. The images were reconstructed
at 8.5, 8.9, 9.7, 10.5, 11.3, 12.0, and 12.7 micrometers. The images
are given in Fig. 3 of the paper. <P />(2 data files).
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Title: MATISSE, the VLTI mid-infrared imaging spectro-interferometer
Authors: Lopez, B.; Lagarde, S.; Petrov, R. G.; Jaffe, W.; Antonelli,
P.; Allouche, F.; Berio, P.; Matter, A.; Meilland, A.; Millour,
F.; Robbe-Dubois, S.; Henning, Th.; Weigelt, G.; Glindemann, A.;
Agocs, T.; Bailet, Ch.; Beckmann, U.; Bettonvil, F.; van Boekel, R.;
Bourget, P.; Bresson, Y.; Bristow, P.; Cruzalèbes, P.; Eldswijk,
E.; Fanteï Caujolle, Y.; González Herrera, J. C.; Graser, U.;
Guajardo, P.; Heininger, M.; Hofmann, K. -H.; Kroes, G.; Laun, W.;
Lehmitz, M.; Leinert, C.; Meisenheimer, K.; Morel, S.; Neumann, U.;
Paladini, C.; Percheron, I.; Riquelme, M.; Schoeller, M.; Stee, Ph.;
Venema, L.; Woillez, J.; Zins, G.; Ábrahám, P.; Abadie, S.; Abuter,
R.; Accardo, M.; Adler, T.; Alonso, J.; Augereau, J. -C.; Böhm, A.;
Bazin, G.; Beltran, J.; Bensberg, A.; Boland, W.; Brast, R.; Burtscher,
L.; Castillo, R.; Chelli, A.; Cid, C.; Clausse, J. -M.; Connot, C.;
Conzelmann, R. D.; Danchi, W. -C.; Delbo, M.; Drevon, J.; Dominik,
C.; van Duin, A.; Ebert, M.; Eisenhauer, F.; Flament, S.; Frahm, R.;
Gámez Rosas, V.; Gabasch, A.; Gallenne, A.; Garces, E.; Girard, P.;
Glazenborg, A.; Gonté, F. Y. J.; Guitton, F.; de Haan, M.; Hanenburg,
H.; Haubois, X.; Hocdé, V.; Hogerheijde, M.; ter Horst, R.; Hron,
J.; Hummel, C. A.; Hubin, N.; Huerta, R.; Idserda, J.; Isbell, J. W.;
Ives, D.; Jakob, G.; Jaskó, A.; Jochum, L.; Klarmann, L.; Klein,
R.; Kragt, J.; Kuindersma, S.; Kokoulina, E.; Labadie, L.; Lacour,
S.; Leftley, J.; Le Poole, R.; Lizon, J. -L.; Lopez, M.; Lykou, F.;
Mérand, A.; Marcotto, A.; Mauclert, N.; Maurer, T.; Mehrgan, L. H.;
Meisner, J.; Meixner, K.; Mellein, M.; Menut, J. L.; Mohr, L.; Mosoni,
L.; Navarro, R.; Nußbaum, E.; Pallanca, L.; Pantin, E.; Pasquini, L.;
Phan Duc, T.; Pott, J. -U.; Pozna, E.; Richichi, A.; Ridinger, A.;
Rigal, F.; Rivinius, Th.; Roelfsema, R.; Rohloff, R. -R.; Rousseau,
S.; Salabert, D.; Schertl, D.; Schuhler, N.; Schuil, M.; Shabun,
K.; Soulain, A.; Stephan, C.; Toledo, P.; Tristram, K.; Tromp, N.;
Vakili, F.; Varga, J.; Vinther, J.; Waters, L. B. F. M.; Wittkowski,
M.; Wolf, S.; Wrhel, F.; Yoffe, G.
2022A&A...659A.192L Altcode: 2021arXiv211015556L
Context. Optical interferometry is at a key development stage. The
Very Large Telescope Interferometer (VLTI) has established a
stable, robust infrastructure for long-baseline interferometry
that is usable by general astronomical observers. The present
second-generation instruments offer a wide wavelength coverage and
improved performance. Their sensitivity and measurement accuracy
lead to data and images of high reliability. <BR /> Aims: We have
developed the Multi AperTure mid-Infrared SpectroScopic Experiment
(MATISSE) to access, for the first time, high resolution imaging
in a wide spectral domain. Many front-line topics are explored with
this new equipment, including: stellar activity and mass loss; planet
formation and evolution in the gas and dust disks around young stars;
and environment interaction and accretion processes around super massive
black holes in active galactic nuclei. <BR /> Methods: The instrument
is a spectro-interferometric imager in the transmission windows called
L, M, and N, from 2.8 to 13.0 microns, combining four optical beams
from the VLTI's unit or auxiliary telescopes. Its concept, related
observing procedure, data reduction, and calibration approach, is the
product of 30 years of instrumental research and has benefitted from
the expertise developed in the frame of the VLTI's first generation
instruments. The instrument utilises a multi-axial beam combination
that delivers spectrally dispersed fringes. The signal provides the
following quantities at several spectral resolutions: photometric flux,
coherent fluxes, visibilities, closure phases, wavelength differential
visibilities and phases, and aperture-synthesis imaging. <BR /> Results:
This article provides an overview of the physical principle of the
instrument and its functionalities. The motivation of the choice of the
instrumental concept and the characteristics of the delivered signal
are detailed with a description of the observing modes and of their
performance limit. MATISSE offers four spectral resolutions in L&M
bands, namely 30, 500, 1000 and 3400, and 30 and 220 in the N band,
and it provides an angular resolution down to 3 mas for the shortest
wavelengths. The MATISSE stand-alone sensitivity limits are 60 mJy in
L and 300 mJy in N. The paper gives details of the sensitivity limits
for the different measurables and their related precision criteria,
considering telescope configurations and spectral resolutions. We
also discuss the gain provided with the GRA4MAT fringe tracker. An
ensemble of data and reconstructed images illustrate the first
acquired key observations. <BR /> Conclusions: The instrument has
been in operation at Cerro Paranal, ESO, Chile, since 2018, and has
been open for science use by the international community since April
2019. The first scientific results are being published now.
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Title: The extended atmosphere and circumstellar environment of the
cool evolved star VX Sagittarii as seen by MATISSE
Authors: Chiavassa, A.; Kravchenko, K.; Montargès, M.; Millour, F.;
Matter, A.; Freytag, B.; Wittkowski, M.; Hocdé, V.; Cruzalèbes, P.;
Allouche, F.; Lopez, B.; Lagarde, S.; Petrov, R. G.; Meilland, A.;
Robbe-Dubois, S.; Hofmann, K. -H.; Weigelt, G.; Berio, P.; Bendjoya,
P.; Bettonvil, F.; Domiciano de Souza, A.; Heininger, M.; Henning, Th.;
Isbell, J. W.; Jaffe, W.; Labadie, L.; Lehmitz, M.; Meisenheimer, K.;
Soulain, A.; Varga, J.; Augereau, J. -C.; van Boekel, R.; Burtscher,
L.; Danchi, W. C.; Dominik, C.; Drevon, J.; Gámez Rosas, V.;
Hogerheijde, M. R.; Hron, J.; Klarmann, L.; Kokoulina, E.; Lagadec,
E.; Leftley, J.; Mosoni, L.; Nardetto, N.; Paladini, C.; Pantin, E.;
Schertl, D.; Stee, P.; Szabados, L.; Waters, R.; Wolf, S.; Yoffe, G.
2022A&A...658A.185C Altcode: 2021arXiv211210695C
Context. VX Sgr is a cool, evolved, and luminous red star whose
stellar parameters are difficult to determine, which affects
its classification. <BR /> Aims: We aim to spatially resolve the
photospheric extent as well as the circumstellar environment. <BR
/> Methods: We used interferometric observations obtained with
the MATISSE instrument in the L (3-4 μm), M (4.5-5 μm), and N
(8-13 μm) bands. We reconstructed monochromatic images using
the MIRA software. We used 3D radiation-hydrodynamics simulations
carried out with CO<SUP>5</SUP>BOLD and a uniform disc model to
estimate the apparent diameter and interpret the stellar surface
structures. Moreover, we employed the radiative transfer codes OPTIM3D
and RADMC3D to compute the spectral energy distribution for the L,
M, and N bands, respectively. <BR /> Results: MATISSE observations
unveil, for the first time, the morphology of VX Sgr across the L, M,
and N bands. The reconstructed images show a complex morphology with
brighter areas whose characteristics depend on the wavelength probed. We
measured the angular diameter as a function of the wavelength and
showed that the photospheric extent in the L and M bands depends on the
opacity through the atmosphere. In addition to this, we also concluded
that the observed photospheric inhomogeneities can be interpreted
as convection-related surface structures. The comparison in the N
band yielded a qualitative agreement between the N-band spectrum
and simple dust radiative transfer simulations. However, it is not
possible to firmly conclude on the interpretation of the current
data because of the difficulty in constraing the model parameters
using the limited accuracy of our absolute flux calibration. <BR />
Conclusions: MATISSE observations and the derived reconstructed images
unveil the appearance of VX Sgr's stellar surface and circumstellar
environment across a very large spectral domain for the first time. <P
/>Based on the observations made with VLTI-ESO Paranal, Chile under
the programme IDs 0103.D-0153(D, E, G). The data are available at <A
href="http://oidb.jmmc.fr/index.html">oidb.jmmc.fr</A>
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Title: VLTI-MATISSE L- and N-band aperture-synthesis imaging of the
unclassified B[e] star FS Canis Majoris
Authors: Hofmann, K. -H.; Bensberg, A.; Schertl, D.; Weigelt, G.;
Wolf, S.; Meilland, A.; Millour, F.; Waters, L. B. F. M.; Kraus,
S.; Ohnaka, K.; Lopez, B.; Petrov, R. G.; Lagarde, S.; Berio, Ph.;
Allouche, F.; Robbe-Dubois, S.; Jaffe, W.; Henning, Th.; Paladini, C.;
Schöller, M.; Mérand, A.; Glindemann, A.; Beckmann, U.; Heininger,
M.; Bettonvil, F.; Zins, G.; Woillez, J.; Bristow, P.; Stee, P.;
Vakili, F.; van Boekel, R.; Hogerheijde, M. R.; Dominik, C.; Augereau,
J. -C.; Matter, A.; Hron, J.; Pantin, E.; Rivinius, Th.; de Wit,
W. -J.; Varga, J.; Klarmann, L.; Meisenheimer, K.; Gámez Rosas,
V.; Burtscher, L.; Leftley, J.; Isbell, J. W.; Yoffe, G.; Kokoulina,
E.; Danchi, W. C.; Cruzalèbes, P.; Domiciano de Souza, A.; Drevon,
J.; Hocdé, V.; Kreplin, A.; Labadie, L.; Connot, C.; Nußbaum, E.;
Lehmitz, M.; Antonelli, P.; Graser, U.; Leinert, C.
2022A&A...658A..81H Altcode: 2021arXiv211112458H
Context. FS Canis Majoris (FS CMa, HD 45677) is an unclassified B[e]
star surrounded by an inclined dust disk. The evolutionary stage of
FS CMa is still debated. Perpendicular to the circumstellar disk,
a bipolar outflow was detected. Infrared aperture-synthesis imaging
provides us with a unique opportunity to study the disk structure. <BR
/> Aims: Our aim is to study the intensity distribution of the
disk of FS CMa in the mid-infrared L and N bands. <BR /> Methods:
We performed aperture-synthesis imaging of FS CMa with the MATISSE
instrument (Multi AperTure mid-Infrared SpectroScopic Experiment)
in the low spectral resolution mode to obtain images in the L and N
bands. We computed radiative transfer models that reproduce the L-
and N-band intensity distributions of the resolved disks. <BR />
Results: We present L- and N-band aperture-synthesis images of FS CMa
reconstructed in the wavelength bands of 3.4-3.8 and 8.6-9.0 μm. In
the L-band image, the inner rim region of an inclined circumstellar
disk and the central object can be seen with a spatial resolution of
2.7 milliarcsec (mas). An inner disk cavity with an angular diameter
of ~6 × 12 mas is resolved. The L-band disk consists of a bright
northwestern (NW) disk region and a much fainter southeastern (SE)
region. The images suggest that we are looking at the bright inner
wall of the NW disk rim, which is on the far side of the disk. In the N
band, only the bright NW disk region is seen. In addition to deriving
the inclination and the inner disk radius, fitting the reconstructed
brightness distributions via radiative transfer modelling allows one
to constrain the innermost disk structure, in particular the shape of
theinner disk rim. <P />Based on observations collected at the European
Organisation for Astronomical Research in the Southern Hemisphere within
the commissioning of the VLTI-MATISSE instrument (ID 60.A-9257(E)).
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Title: Thermal imaging of dust hiding the black hole in NGC 1068
Authors: Gámez Rosas, Violeta; Isbell, Jacob W.; Jaffe, Walter;
Petrov, Romain G.; Leftley, James H.; Hofmann, Karl-Heinz; Millour,
Florentin; Burtscher, Leonard; Meisenheimer, Klaus; Meilland, Anthony;
Waters, Laurens B. F. M.; Lopez, Bruno; Lagarde, Stéphane; Weigelt,
Gerd; Berio, Philippe; Allouche, Fatme; Robbe-Dubois, Sylvie;
Cruzalèbes, Pierre; Bettonvil, Felix; Henning, Thomas; Augereau,
Jean-Charles; Antonelli, Pierre; Beckmann, Udo; van Boekel, Roy;
Bendjoya, Philippe; Danchi, William C.; Dominik, Carsten; Drevon,
Julien; Gallimore, Jack F.; Graser, Uwe; Heininger, Matthias;
Hocdé, Vincent; Hogerheijde, Michiel; Hron, Josef; Impellizzeri,
Caterina M. V.; Klarmann, Lucia; Kokoulina, Elena; Labadie, Lucas;
Lehmitz, Michael; Matter, Alexis; Paladini, Claudia; Pantin, Eric;
Pott, Jörg-Uwe; Schertl, Dieter; Soulain, Anthony; Stee, Philippe;
Tristram, Konrad; Varga, Jozsef; Woillez, Julien; Wolf, Sebastian;
Yoffe, Gideon; Zins, Gerard
2022Natur.602..403G Altcode: 2021arXiv211213694G
In the widely accepted `unified model'<SUP>1</SUP> solution of the
classification puzzle of active galactic nuclei, the orientation of a
dusty accretion torus around the central black hole dominates their
appearance. In `type-1' systems, the bright nucleus is visible at
the centre of a face-on torus. In `type-2' systems the thick, nearly
edge-on torus hides the central engine. Later studies suggested
evolutionary effects<SUP>2</SUP> and added dusty clumps and polar
winds<SUP>3</SUP> but left the basic picture intact. However, recent
high-resolution images<SUP>4</SUP> of the archetypal type-2 galaxy
NGC 1068<SUP>5,6</SUP>, suggested a more radical revision. The images
displayed a ring-like emission feature that was proposed to be hot dust
surrounding the black hole at the radius where the radiation from the
central engine evaporates the dust. That ring is too thin and too far
tilted from edge-on to hide the central engine, and ad hoc foreground
extinction is needed to explain the type-2 classification. These images
quickly generated reinterpretations of the dichotomy between types 1
and 2<SUP>7,8</SUP>. Here we present new multi-band mid-infrared images
of NGC 1068 that detail the dust temperature distribution and reaffirm
the original model. Combined with radio data (J.F.G. and C.M.V.I.,
manuscript in preparation), our maps locate the central engine that
is below the previously reported ring and obscured by a thick, nearly
edge-on disk, as predicted by the unified model. We also identify
emission from polar flows and absorbing dust that is mineralogically
distinct from that towards the Milky Way centre.
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Title: Simultaneous broadband radio and optical emission of meteor
trains imaged by LOFAR / AARTFAAC and CAMS
Authors: Dijkema, Tammo Jan; Bassa, Cees; Kuiack, Mark; Jenniskens,
Peter; Johannink, Carl; Bettonvil, Felix; Wijers, Ralph; Fallows,
Richard
2021JIMO...49..137D Altcode: 2021arXiv211109742D
We report on simultaneous 30 - 60 MHz LOFAR / AARTFAAC12 radio
observations and CAMS low-light video observations of +4 to -10
magnitude meteors at the peak of the Perseid meteor shower on August
12/13, 2020. 204 meteor trains were imaged in both the radio and
optical domain. Aside from scattered artificial radio sources, we
identify broadband radio emission from many persistent trains, one of
which lingered for up to 6 minutes. Unexpectedly, fewer broadband radio
meteor trains were recorded when the experiment was repeated during
the 2020 Geminids and 2021 Quadrantids. Intrinsic broadband radio
emission was reported earlier by the Long Wavelength Array, but for
much brighter meteors and observed with lower spatial resolution. The
new results offer insight into the unknown radio emission mechanism.
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Title: First MATISSE L-band observations of HD 179218. Is the inner
10 au region rich in carbon dust particles?
Authors: Kokoulina, E.; Matter, A.; Lopez, B.; Pantin, E.; Ysard, N.;
Weigelt, G.; Habart, E.; Varga, J.; Jones, A.; Meilland, A.; Dartois,
E.; Klarmann, L.; Augereau, J. -C.; van Boekel, R.; Hogerheijde, M.;
Yoffe, G.; Waters, L. B. F. M.; Dominik, C.; Jaffe, W.; Millour, F.;
Henning, Th.; Hofmann, K. -H.; Schertl, D.; Lagarde, S.; Petrov,
R. G.; Antonelli, P.; Allouche, F.; Berio, P.; Robbe-Dubois, S.;
Ábraham, P.; Beckmann, U.; Bensberg, A.; Bettonvil, F.; Bristow, P.;
Cruzalèbes, P.; Danchi, W. C.; Dannhoff, M.; Graser, U.; Heininger,
M.; Labadie, L.; Lehmitz, M.; Leinert, C.; Meisenheimer, K.; Paladini,
C.; Percheron, I.; Stee, Ph.; Woillez, J.; Wolf, S.; Zins, G.; Delbo,
M.; Drevon, J.; Duprat, J.; Gámez Rosas, V.; Hocdé, V.; Hron, J.;
Hummel, C. A.; Isbell, J. W.; Leftley, J.; Soulain, A.; Vakili, F.;
Wittkowski, M.
2021A&A...652A..61K Altcode: 2021arXiv210612947K
Context. Carbon is one of the most abundant components in the
Universe. While silicates have been the main focus of solid phase
studies in protoplanetary discs (PPDs), little is known about the
solid carbon content especially in the planet-forming regions (~0.1-10
au). Fortunately, several refractory carbonaceous species present C-H
bonds (such as hydrogenated nano-diamond and amorphous carbon as well
as polycyclic aromatic hydrocarbons), which generate infrared (IR)
features that can be used to trace the solid carbon reservoirs. The
new mid-IR instrument MATISSE, installed at the Very Large Telescope
Interferometer (VLTI), can spatially resolve the inner regions (~1-10
au) of PPDs and locate, down to the au-scale, the emission coming
from carbon grains. <BR /> Aims: Our aim is to provide a consistent
view on the radial structure, down to the au-scale, as well as basic
physical properties and the nature of the material responsible for the
IR continuum emission in the inner disk region around HD 179218. <BR
/> Methods: We implemented a temperature-gradient model to interpret
the disk IR continuum emission, based on a multiwavelength dataset
comprising a broadband spectral energy distribution and VLTI H-, L-, and
N-bands interferometric data obtained in low spectral resolution. Then,
we added a ring-like component, representing the carbonaceous L-band
features-emitting region, to assess its detectability in future higher
spectral resolution observations employing mid-IR interferometry. <BR />
Results: Our temperature-gradient model can consistently reproduce our
dataset. We confirmed a spatially extended inner 10 au emission in H-
and L-bands, with a homogeneously high temperature (~1700 K), which we
associate with the presence of stochastically heated nano-grains. On the
other hand, the N-band emitting region presents a ring-like geometry
that starts at about 10 au with a temperature of 400 K. Moreover, the
existing low resolution MATISSE data exclude the presence of aromatic
carbon grains (i.e., producing the 3.3 μm feature) in close proximity
tothe star (≲1 au). Future medium spectral resolution MATISSE data
will confirm their presence at larger distances. <BR /> Conclusions:
Our best-fit model demonstrates the presence of two separated dust
populations: nano-grains that dominate the near- to mid-IR emission
in the inner 10 au region and larger grains that dominate the emission
outward. The presence of such nano-grains in the highly irradiated inner
10 au region of HD 179218 requires a replenishment process. Considering
the expected lifetime of carbon nano-grains from The Heterogeneous dust
Evolution Model for Interstellar Solids (THEMIS model), the estimated
disk accretion inflow of HD 179218 could significantly contribute to
feed the inner 10 au region in nano-grains.Moreover, we also expect a
local regeneration of those nano-grains by the photo-fragmentation of
larger aggregates. <P />Based on observations collected at the European
Southern Observatory, Chile (ESO ID: 0103.D-0069).
---------------------------------------------------------
Title: VLTI-MATISSE chromatic aperture-synthesis imaging of η
Carinae's stellar wind across the Brα line. Periastron passage
observations in February 2020
Authors: Weigelt, G.; Hofmann, K. -H.; Schertl, D.; Lopez, B.;
Petrov, R. G.; Lagarde, S.; Berio, Ph.; Jaffe, W.; Henning, Th.;
Millour, F.; Meilland, A.; Allouche, F.; Robbe-Dubois, S.; Matter,
A.; Cruzalèbes, P.; Hillier, D. J.; Russell, C. M. P.; Madura, T.;
Gull, T. R.; Corcoran, M. F.; Damineli, A.; Moffat, A. F. J.; Morris,
P. W.; Richardson, N. D.; Paladini, C.; Schöller, M.; Mérand, A.;
Glindemann, A.; Beckmann, U.; Heininger, M.; Bettonvil, F.; Zins, G.;
Woillez, J.; Bristow, P.; Sanchez-Bermudez, J.; Ohnaka, K.; Kraus,
S.; Mehner, A.; Wittkowski, M.; Hummel, C. A.; Stee, P.; Vakili, F.;
Hartman, H.; Navarete, F.; Hamaguchi, K.; Espinoza-Galeas, D. A.;
Stevens, I. R.; van Boekel, R.; Wolf, S.; Hogerheijde, M. R.; Dominik,
C.; Augereau, J. -C.; Pantin, E.; Waters, L. B. F. M.; Meisenheimer,
K.; Varga, J.; Klarmann, L.; Gámez Rosas, V.; Burtscher, L.; Leftley,
J.; Isbell, J. W.; Hocdé, V.; Yoffe, G.; Kokoulina, E.; Hron, J.;
Groh, J.; Kreplin, A.; Rivinius, Th.; de Wit, W. -J.; Danchi, W. -C.;
Domiciano de Souza, A.; Drevon, J.; Labadie, L.; Connot, C.; Nußbaum,
E.; Lehmitz, M.; Antonelli, P.; Graser, U.; Leinert, C.
2021A&A...652A.140W Altcode:
Context. Eta Carinae is a highly eccentric, massive binary
system (semimajor axis ~15.5 au) with powerful stellar winds and
a phase-dependent wind-wind collision (WWC) zone. The primary
star, η Car A, is a luminous blue variable (LBV); the secondary,
η Car B, is a Wolf-Rayet or O star with a faster but less dense
wind. Aperture-synthesis imaging allows us to study the mass loss from
the enigmatic LBV η Car. Understanding LBVs is a crucial step toward
improving our knowledge about massive stars and their evolution. <BR />
Aims: Our aim is to study the intensity distribution and kinematics of
η Car's WWC zone. <BR /> Methods: Using the VLTI-MATISSE mid-infrared
interferometry instrument, we perform Brα imaging of η Car's
distorted wind. <BR /> Results: We present the first VLTI-MATISSE
aperture-synthesis images of η Car A's stellar windin several spectral
channels distributed across the Brα 4.052 μm line (spectral resolving
power R ~ 960). Our observations were performed close to periastron
passage in February 2020 (orbital phase ~ 14.0022). The reconstructed
iso-velocity images show the dependence of the primary stellar
wind on wavelength or line-of-sight (LOS) velocity with a spatial
resolution of 6 mas (~14 au). The radius of the faintest outer wind
regions is ~26 mas (~60 au). At several negative LOS velocities, the
primary stellar wind is less extended to the northwest than in other
directions. This asymmetry is most likely caused by the WWC. Therefore,
we see both the velocity field of the undisturbed primary wind and the
WWC cavity. In continuum spectral channels, the primary star wind is
more compact than in line channels. A fit of the observed continuum
visibilities with the visibilities of a stellar wind CMFGEN model
(CMFGEN is an atmosphere code developed to model the spectra of a
variety of objects) provides a full width at half maximum fit diameter
of the primary stellar wind of 2.84 ± 0.06 mas (6.54 ± 0.14 au). We
comparethe derived intensity distributions with the CMFGEN stellar
wind model and hydrodynamic WWC models. <P />Based on observations
collected at the European Organisation for Astronomical Research in
the Southern Hemisphere under ESO program 0104.D-0015A, 0104.D-0015B,
0104.D-0015C, 0106.D-0309(A), 0106.D-0309(B), and 0106.D-0309(C).
---------------------------------------------------------
Title: Mid-infrared circumstellar emission of the long-period Cepheid
ℓ Carinae resolved with VLTI/MATISSE
Authors: Hocdé, V.; Nardetto, N.; Matter, A.; Lagadec, E.; Mérand,
A.; Cruzalèbes, P.; Meilland, A.; Millour, F.; Lopez, B.; Berio,
P.; Weigelt, G.; Petrov, R.; Isbell, J. W.; Jaffe, W.; Kervella, P.;
Glindemann, A.; Schöller, M.; Allouche, F.; Gallenne, A.; Domiciano
de Souza, A.; Niccolini, G.; Kokoulina, E.; Varga, J.; Lagarde, S.;
Augereau, J. -C.; van Boekel, R.; Bristow, P.; Henning, Th.; Hofmann,
K. -H.; Zins, G.; Danchi, W. -C.; Delbo, M.; Dominik, C.; Gámez
Rosas, V.; Klarmann, L.; Hron, J.; Hogerheijde, M. R.; Meisenheimer,
K.; Pantin, E.; Paladini, C.; Robbe-Dubois, S.; Schertl, D.; Stee,
P.; Waters, R.; Lehmitz, M.; Bettonvil, F.; Heininger, M.; Bristow,
P.; Woillez, J.; Wolf, S.; Yoffe, G.; Szabados, L.; Chiavassa, A.;
Borgniet, S.; Breuval, L.; Javanmardi, B.; Ábrahám, P.; Abadie, S.;
Abuter, R.; Accardo, M.; Adler, T.; Agócs, T.; Alonso, J.; Antonelli,
P.; Böhm, A.; Bailet, C.; Bazin, G.; Beckmann, U.; Beltran, J.;
Boland, W.; Bourget, P.; Brast, R.; Bresson, Y.; Burtscher, L.;
Buter, R.; Castillo, R.; Chelli, A.; Cid, C.; Clausse, J. -M.; Connot,
C.; Conzelmann, R. D.; De Haan, M.; Ebert, M.; Elswijk, E.; Fantei,
Y.; Frahm, R.; Gámez Rosas, V.; Gabasch, A.; Garces, E.; Girard,
P.; Glazenborg, A.; Gonté, F. Y. J.; González Herrera, J. C.;
Graser, U.; Guajardo, P.; Guitton, F.; Hanenburg, H.; Haubois, X.;
Hubin, N.; Huerta, R.; Idserda, J.; Ives, D.; Jakob, G.; Jaskó,
A.; Jochum, L.; Klein, R.; Kragt, J.; Kroes, G.; Kuindersma, S.;
Labadie, L.; Laun, W.; Le Poole, R.; Leinert, C.; Lizon, J. -L.;
Lopez, M.; Marcotto, A.; Mauclert, N.; Maurer, T.; Mehrgan, L. H.;
Meisner, J.; Meixner, K.; Mellein, M.; Mohr, L.; Morel, S.; Mosoni,
L.; Navarro, R.; Neumann, U.; Nußbaum, E.; Pallanca, L.; Pasquini,
L.; Percheron, I.; Phan Duc, T.; Pott, J. -U.; Pozna, E.; Ridinger,
A.; Rigal, F.; Riquelme, M.; Rivinius, Th.; Roelfsema, R.; Rohloff,
R. -R.; Rousseau, S.; Schuhler, N.; Schuil, M.; Shabun, K.; Soulain,
A.; Stephan, C.; ter Horst, R.; Tromp, N.; Vakili, F.; van Duin, A.;
Venema, L. B.; Vinther, J.; Wittkowski, M.; Wrhel, F.
2021A&A...651A..92H Altcode: 2021arXiv210317014H
Context. The nature of circumstellar envelopes (CSEs) around Cepheids
is a matter of ongoing debate. The physical origin of their infrared
(IR) excess could be shown to either be made up of a shell of ionized
gas, a dust envelope, or a combination of both. <BR /> Aims: This
study is aimed at constraining the geometry and the IR excess of the
environment of the bright long-period Cepheid ℓ Car (P = 35.5 days)
at mid-IR wavelengths in order to understand its physical nature. <BR
/> Methods: We first used photometric observations in various bands
(from the visible domain to the infrared) and Spitzer Space Telescope
spectroscopy to constrain the IR excess of ℓ Car. Then we analyzed
the VLTI/MATISSE measurements at a specific phase of observation
in order to determine the flux contribution as well as the size and
shape of the environment of the star in the L band. Finally, we tested
the hypothesis of a shell of ionized gas in order to model the IR
excess. <BR /> Results: We report the first detection in the L band
of a centro-symmetric extended emission around ℓ Car, of about 1.7
R<SUB>⋆</SUB> in full width at half maximum, producing an excess of
about 7.0% in this band.This latter value is used to calibrate the IR
excess found when comparing the photometric observations in various
bands and quasi-static atmosphere models. In the N band, there is no
clear evidence for dust emission from VLTI/MATISSE correlated flux
and Spitzer data. On the other side, the modeled shell of ionized
gas implies a more compact CSE (1.13 ± 0.02 R<SUB>⋆</SUB>) that
is also fainter (IR excess of 1% in the L band). <BR /> Conclusions:
We provide new evidence supporting a compact CSE for ℓ Car and we
demonstrate the capabilities of VLTI/MATISSE for determining common
properties of CSEs. While the compact CSE of ℓ Car is likely to be
of a gaseous nature, the tested model of a shell of ionized gas is not
able to simultaneously reproduce the IR excess and the interferometric
observations. Further Galactic Cepheid observations with VLTI/MATISSE
are necessary for determining the properties of CSEs, which may also
depend on both the pulsation period and the evolutionary state of the
stars. <P />Based on observations made with ESO telescopes at Paranal
observatory under program ID 0104.D-0554(A).
---------------------------------------------------------
Title: Trajectory and orbit of the unique carbonaceous meteorite
Flensburg
Authors: Borovička, Jiří; Bettonvil, Felix; Baumgarten, Gerd;
Strunk, Jörg; Hankey, Mike; Spurný, Pavel; Heinlein, Dieter
2021M&PS...56..425B Altcode: 2021arXiv210102177B
The C1 ungrouped carbonaceous chondrite Flensburg fell in Germany
on September 12, 2019, in the daytime. We determined the atmospheric
trajectory, velocity, and heliocentric orbit using one dedicated AllSky6
meteor camera and three casual video records of the bolide. It was found
that the meteorite originated in the vicinity of the 5:2 resonance with
Jupiter at heliocentric distance of 2.82 AU. When combined with the
bolide energy reported by the United States government sensors (USGS),
the preatmospheric diameter of the meteoroid was estimated to be 2-3 m
and the mass to be 10,000-20,000 kg. The meteoroid fragmented heavily
in the atmosphere at heights of 46-37 km, under dynamic pressures of
0.7-2 MPa. The recovery of just one meteorite suggests that only a
very small part of the original mass reached the ground. The bolide
velocity vector was compared with that reported by the USGS. There
is good agreement in the radiant but the velocity value has been
underestimated by the USGS by almost 1 km s<SUP>−1</SUP>.
---------------------------------------------------------
Title: The asymmetric inner disk of the Herbig Ae star HD 163296 in
the eyes of VLTI/MATISSE: evidence for a vortex?
Authors: Varga, J.; Hogerheijde, M.; van Boekel, R.; Klarmann, L.;
Petrov, R.; Waters, L. B. F. M.; Lagarde, S.; Pantin, E.; Berio,
Ph.; Weigelt, G.; Robbe-Dubois, S.; Lopez, B.; Millour, F.; Augereau,
J. -C.; Meheut, H.; Meilland, A.; Henning, Th.; Jaffe, W.; Bettonvil,
F.; Bristow, P.; Hofmann, K. -H.; Matter, A.; Zins, G.; Wolf, S.;
Allouche, F.; Donnan, F.; Schertl, D.; Dominik, C.; Heininger, M.;
Lehmitz, M.; Cruzalèbes, P.; Glindemann, A.; Meisenheimer, K.;
Paladini, C.; Schöller, M.; Woillez, J.; Venema, L.; Kokoulina,
E.; Yoffe, G.; Ábrahám, P.; Abadie, S.; Abuter, R.; Accardo, M.;
Adler, T.; Agócs, T.; Antonelli, P.; Böhm, A.; Bailet, C.; Bazin, G.;
Beckmann, U.; Beltran, J.; Boland, W.; Bourget, P.; Brast, R.; Bresson,
Y.; Burtscher, L.; Castillo, R.; Chelli, A.; Cid, C.; Clausse, J. -M.;
Connot, C.; Conzelmann, R. D.; Danchi, W. -C.; De Haan, M.; Delbo,
M.; Ebert, M.; Elswijk, E.; Fantei, Y.; Frahm, R.; Gámez Rosas, V.;
Gabasch, A.; Gallenne, A.; Garces, E.; Girard, P.; Gonté, F. Y. J.;
González Herrera, J. C.; Graser, U.; Guajardo, P.; Guitton, F.;
Haubois, X.; Hron, J.; Hubin, N.; Huerta, R.; Isbell, J. W.; Ives,
D.; Jakob, G.; Jaskó, A.; Jochum, L.; Klein, R.; Kragt, J.; Kroes,
G.; Kuindersma, S.; Labadie, L.; Laun, W.; Le Poole, R.; Leinert, C.;
Lizon, J. -L.; Lopez, M.; Mérand, A.; Marcotto, A.; Mauclert, N.;
Maurer, T.; Mehrgan, L. H.; Meisner, J.; Meixner, K.; Mellein, M.;
Mohr, L.; Morel, S.; Mosoni, L.; Navarro, R.; Neumann, U.; Nußbaum,
E.; Pallanca, L.; Pasquini, L.; Percheron, I.; Pott, J. -U.; Pozna,
E.; Ridinger, A.; Rigal, F.; Riquelme, M.; Rivinius, Th.; Roelfsema,
R.; Rohloff, R. -R.; Rousseau, S.; Schuhler, N.; Schuil, M.; Soulain,
A.; Stee, P.; Stephan, C.; ter Horst, R.; Tromp, N.; Vakili, F.;
van Duin, A.; Vinther, J.; Wittkowski, M.; Wrhel, F.
2021A&A...647A..56V Altcode: 2020arXiv201205697V
Context. A complex environment exists in the inner few astronomical
units of planet-forming disks. High-angular-resolution observations
play a key role in our understanding of the disk structure and the
dynamical processes at work. <BR /> Aims: In this study we aim to
characterize the mid-infrared brightness distribution of the inner disk
of the young intermediate-mass star HD 163296 from early VLTI/MATISSE
observations taken in the L- and N-bands. We put special emphasis on
the detection of potential disk asymmetries. <BR /> Methods: We use
simple geometric models to fit the interferometric visibilities and
closure phases. Our models include a smoothed ring, a flat disk with
an inner cavity, and a 2D Gaussian. The models can account for disk
inclination and for azimuthal asymmetries as well. We also perform
numerical hydrodynamical simulations of the inner edge of the disk. <BR
/> Results: Our modeling reveals a significant brightness asymmetry in
the L-band disk emission. The brightness maximum of the asymmetry is
located at the NW part of the disk image, nearly at the position angle
of the semimajor axis. The surface brightness ratio in the azimuthal
variation is 3.5 ± 0.2. Comparing our result on the location of the
asymmetry with other interferometric measurements, we confirm that
the morphology of the r < 0.3 au disk region is time-variable. We
propose that this asymmetric structure, located in or near the inner
rim of the dusty disk, orbits the star. To find the physical origin
of the asymmetry, we tested a hypothesis where a vortex is created
by Rossby wave instability, and we find that a unique large-scale
vortex may be compatible with our data. The half-light radius of
the L-band-emitting region is 0.33 ±0.01 au, the inclination is
52°<SUB>-7°</SUB><SUP>+5°</SUP>, and the position angle is 143°
± 3°. Our models predict that a non-negligible fraction of the
L-band disk emission originates inside the dust sublimation radius
for μm-sized grains. Refractory grains or large (≳10 μm-sized)
grains could be the origin of this emission. N-band observations may
also support a lack of small silicate grains in the innermost disk
(r ≲ 0.6 au), in agreement with our findings from L-band data. <P
/>Based on observations made with ESO Telescopes at the La Silla
Paranal Observatory under program IDs 0103.D-0294 and 0103.D-0153.
---------------------------------------------------------
Title: METIS: The Mid-infrared ELT Imager and Spectrograph
Authors: Brandl, B.; Bettonvil, F.; van Boekel, R.; Glauser, A.; Quanz,
S.; Absil, O.; Amorim, A.; Feldt, M.; Glasse, A.; Güdel, M.; Ho, P.;
Labadie, L.; Meyer, M.; Pantin, E.; van Winckel, H.; METIS Consortium
2021Msngr.182...22B Altcode: 2021arXiv210311208B
The Mid-infrared ELT Imager and Spectrograph (METIS) will provide the
Extremely Large Telescope (ELT) with a unique window to the thermal-
and mid-infrared (3-13 µm). Its single-conjugate adaptive optics
(SCAO) system will enable high contrast imaging and integral field
unit (IFU) spectroscopy (R ~ 100 000) at the diffraction limit of the
ELT. This article describes the science drivers, conceptual design,
observing modes, and expected performance of METIS.
---------------------------------------------------------
Title: FRIPON: a worldwide network to track incoming meteoroids
Authors: Colas, F.; Zanda, B.; Bouley, S.; Jeanne, S.; Malgoyre, A.;
Birlan, M.; Blanpain, C.; Gattacceca, J.; Jorda, L.; Lecubin, J.;
Marmo, C.; Rault, J. L.; Vaubaillon, J.; Vernazza, P.; Yohia, C.;
Gardiol, D.; Nedelcu, A.; Poppe, B.; Rowe, J.; Forcier, M.; Koschny,
D.; Trigo-Rodriguez, J. M.; Lamy, H.; Behrend, R.; Ferrière, L.;
Barghini, D.; Buzzoni, A.; Carbognani, A.; Di Carlo, M.; Di Martino,
M.; Knapic, C.; Londero, E.; Pratesi, G.; Rasetti, S.; Riva, W.;
Stirpe, G. M.; Valsecchi, G. B.; Volpicelli, C. A.; Zorba, S.; Coward,
D.; Drolshagen, E.; Drolshagen, G.; Hernandez, O.; Jehin, E.; Jobin,
M.; King, A.; Nitschelm, C.; Ott, T.; Sanchez-Lavega, A.; Toni,
A.; Abraham, P.; Affaticati, F.; Albani, M.; Andreis, A.; Andrieu,
T.; Anghel, S.; Antaluca, E.; Antier, K.; Appéré, T.; Armand, A.;
Ascione, G.; Audureau, Y.; Auxepaules, G.; Avoscan, T.; Baba Aissa,
D.; Bacci, P.; Bǎdescu, O.; Baldini, R.; Baldo, R.; Balestrero, A.;
Baratoux, D.; Barbotin, E.; Bardy, M.; Basso, S.; Bautista, O.; Bayle,
L. D.; Beck, P.; Bellitto, R.; Belluso, R.; Benna, C.; Benammi, M.;
Beneteau, E.; Benkhaldoun, Z.; Bergamini, P.; Bernardi, F.; Bertaina,
M. E.; Bessin, P.; Betti, L.; Bettonvil, F.; Bihel, D.; Birnbaum,
C.; Blagoi, O.; Blouri, E.; Boacă, I.; Boatǎ, R.; Bobiet, B.;
Bonino, R.; Boros, K.; Bouchet, E.; Borgeot, V.; Bouchez, E.; Boust,
D.; Boudon, V.; Bouman, T.; Bourget, P.; Brandenburg, S.; Bramond,
Ph.; Braun, E.; Bussi, A.; Cacault, P.; Caillier, B.; Calegaro, A.;
Camargo, J.; Caminade, S.; Campana, A. P. C.; Campbell-Burns, P.;
Canal-Domingo, R.; Carell, O.; Carreau, S.; Cascone, E.; Cattaneo,
C.; Cauhape, P.; Cavier, P.; Celestin, S.; Cellino, A.; Champenois,
M.; Chennaoui Aoudjehane, H.; Chevrier, S.; Cholvy, P.; Chomier, L.;
Christou, A.; Cricchio, D.; Coadou, P.; Cocaign, J. Y.; Cochard, F.;
Cointin, S.; Colombi, E.; Colque Saavedra, J. P.; Corp, L.; Costa, M.;
Costard, F.; Cottier, M.; Cournoyer, P.; Coustal, E.; Cremonese, G.;
Cristea, O.; Cuzon, J. C.; D'Agostino, G.; Daiffallah, K.; Dǎnescu,
C.; Dardon, A.; Dasse, T.; Davadan, C.; Debs, V.; Defaix, J. P.;
Deleflie, F.; D'Elia, M.; De Luca, P.; De Maria, P.; Deverchère,
P.; Devillepoix, H.; Dias, A.; Di Dato, A.; Di Luca, R.; Dominici,
F. M.; Drouard, A.; Dumont, J. L.; Dupouy, P.; Duvignac, L.; Egal,
A.; Erasmus, N.; Esseiva, N.; Ebel, A.; Eisengarten, B.; Federici,
F.; Feral, S.; Ferrant, G.; Ferreol, E.; Finitzer, P.; Foucault, A.;
Francois, P.; Frîncu, M.; Froger, J. L.; Gaborit, F.; Gagliarducci,
V.; Galard, J.; Gardavot, A.; Garmier, M.; Garnung, M.; Gautier, B.;
Gendre, B.; Gerard, D.; Gerardi, A.; Godet, J. P.; Grandchamps, A.;
Grouiez, B.; Groult, S.; Guidetti, D.; Giuli, G.; Hello, Y.; Henry, X.;
Herbreteau, G.; Herpin, M.; Hewins, P.; Hillairet, J. J.; Horak, J.;
Hueso, R.; Huet, E.; Huet, S.; Hyaumé, F.; Interrante, G.; Isselin,
Y.; Jeangeorges, Y.; Janeux, P.; Jeanneret, P.; Jobse, K.; Jouin, S.;
Jouvard, J. M.; Joy, K.; Julien, J. F.; Kacerek, R.; Kaire, M.; Kempf,
M.; Koschny, D.; Krier, C.; Kwon, M. K.; Lacassagne, L.; Lachat, D.;
Lagain, A.; Laisné, E.; Lanchares, V.; Laskar, J.; Lazzarin, M.;
Leblanc, M.; Lebreton, J. P.; Lecomte, J.; Le Dû, P.; Lelong, F.;
Lera, S.; Leoni, J. F.; Le-Pichon, A.; Le-Poupon, P.; Leroy, A.; Leto,
G.; Levansuu, A.; Lewin, E.; Lienard, A.; Licchelli, D.; Locatelli,
H.; Loehle, S.; Loizeau, D.; Luciani, L.; Maignan, M.; Manca, F.;
Mancuso, S.; Mandon, E.; Mangold, N.; Mannucci, F.; Maquet, L.;
Marant, D.; Marchal, Y.; Marin, J. L.; Martin-Brisset, J. C.; Martin,
D.; Mathieu, D.; Maury, A.; Mespoulet, N.; Meyer, F.; Meyer, J. Y.;
Meza, E.; Moggi Cecchi, V.; Moiroud, J. J.; Millan, M.; Montesarchio,
M.; Misiano, A.; Molinari, E.; Molau, S.; Monari, J.; Monflier, B.;
Monkos, A.; Montemaggi, M.; Monti, G.; Moreau, R.; Morin, J.; Mourgues,
R.; Mousis, O.; Nablanc, C.; Nastasi, A.; Niacşu, L.; Notez, P.; Ory,
M.; Pace, E.; Paganelli, M. A.; Pagola, A.; Pajuelo, M.; Palacián,
J. F.; Pallier, G.; Paraschiv, P.; Pardini, R.; Pavone, M.; Pavy, G.;
Payen, G.; Pegoraro, A.; Peña-Asensio, E.; Perez, L.; Pérez-Hoyos,
S.; Perlerin, V.; Peyrot, A.; Peth, F.; Pic, V.; Pietronave, S.;
Pilger, C.; Piquel, M.; Pisanu, T.; Poppe, M.; Portois, L.; Prezeau,
J. F.; Pugno, N.; Quantin, C.; Quitté, G.; Rambaux, N.; Ravier, E.;
Repetti, U.; Ribas, S.; Richard, C.; Richard, D.; Rigoni, M.; Rivet,
J. P.; Rizzi, N.; Rochain, S.; Rojas, J. F.; Romeo, M.; Rotaru, M.;
Rotger, M.; Rougier, P.; Rousselot, P.; Rousset, J.; Rousseu, D.;
Rubiera, O.; Rudawska, R.; Rudelle, J.; Ruguet, J. P.; Russo, P.;
Sales, S.; Sauzereau, O.; Salvati, F.; Schieffer, M.; Schreiner, D.;
Scribano, Y.; Selvestrel, D.; Serra, R.; Shengold, L.; Shuttleworth,
A.; Smareglia, R.; Sohy, S.; Soldi, M.; Stanga, R.; Steinhausser, A.;
Strafella, F.; Sylla Mbaye, S.; Smedley, A. R. D.; Tagger, M.; Tanga,
P.; Taricco, C.; Teng, J. P.; Tercu, J. O.; Thizy, O.; Thomas, J. P.;
Tombelli, M.; Trangosi, R.; Tregon, B.; Trivero, P.; Tukkers, A.;
Turcu, V.; Umbriaco, G.; Unda-Sanzana, E.; Vairetti, R.; Valenzuela,
M.; Valente, G.; Varennes, G.; Vauclair, S.; Vergne, J.; Verlinden, M.;
Vidal-Alaiz, M.; Vieira-Martins, R.; Viel, A.; Vîntdevarǎ, D. C.;
Vinogradoff, V.; Volpini, P.; Wendling, M.; Wilhelm, P.; Wohlgemuth,
K.; Yanguas, P.; Zagarella, R.; Zollo, A.
2020A&A...644A..53C Altcode: 2020arXiv201200616C
Context. Until recently, camera networks designed for monitoring
fireballs worldwide were not fully automated, implying that in case of
a meteorite fall, the recovery campaign was rarely immediate. This was
an important limiting factor as the most fragile - hence precious -
meteorites must be recovered rapidly to avoid their alteration. <BR
/> Aims: The Fireball Recovery and InterPlanetary Observation
Network (FRIPON) scientific project was designed to overcome this
limitation. This network comprises a fully automated camera and radio
network deployed over a significant fraction of western Europe and
a small fraction of Canada. As of today, it consists of 150 cameras
and 25 European radio receivers and covers an area of about 1.5 ×
10<SUP>6</SUP> km<SUP>2</SUP>. <BR /> Methods: The FRIPON network,
fully operational since 2018, has been monitoring meteoroid entries
since 2016, thereby allowing the characterization of their dynamical and
physical properties. In addition, the level of automation of the network
makes it possible to trigger a meteorite recovery campaign only a few
hours after it reaches the surface of the Earth. Recovery campaigns
are only organized for meteorites with final masses estimated of at
least 500 g, which is about one event per year in France. No recovery
campaign is organized in the case of smaller final masses on the
order of 50 to 100 g, which happens about three times a year; instead,
the information is delivered to the local media so that it can reach
the inhabitants living in the vicinity of the fall. <BR /> Results:
Nearly 4000 meteoroids have been detected so far and characterized by
FRIPON. The distribution of their orbits appears to be bimodal, with
a cometary population and a main belt population. Sporadic meteors
amount to about 55% of all meteors. A first estimate of the absolute
meteoroid flux (mag < -5; meteoroid size ≥~1 cm) amounts to
1250/yr/10<SUP>6</SUP> km<SUP>2</SUP>. This value is compatible with
previous estimates. Finally, the first meteorite was recovered in Italy
(Cavezzo, January 2020) thanks to the PRISMA network, a component of
the FRIPON science project.
---------------------------------------------------------
Title: Ge immersed grating manufacturing and optical verification
for the METIS high-resolution spectrograph
Authors: Agócs, Tibor; Elswijk, Eddy; Zaalberg, Daan; Peterzon,
Jan Rinze; Tromp, Niels; Lloro, Ivan; Lynn, Jeffrey; Navarro, Ramon;
Sukegawa, Takashi; Okura, Yukinobu; Todd, Stephen; Glasse, Alistair;
Parr-Burman, Philip; Brandl, Bernhard; Bettonvil, Felix
2020SPIE11451E..1GA Altcode:
We present the manufacturing and optical verification of the germanium
immersed grating for the L/M band high resolution spectrograph
(LMS). The LMS is one of the science subsystems of the Mid-infrared
ELT Imager and Spectrograph, METIS. The immersed grating has very
demanding requirement specifications: <100 nm RMS transmitted Wave
Front Error (WFE) after double pass, and >70% peak throughput in
all orders within the 2.9-5.3 μm wavelength range over the pupil. The
grating has a period of 18.2 μm, a sawtooth groove profile with 89.6
degrees apex angle and a grating area of 150mm x 60mm. The germanium
immersed grating was produced by Canon's high precision mechanical
cutting technology. We present the interferometric tests that were
performed in order to verify WFE and two different measurements (based
on cascade laser and Fourier Transform Spectrometer, respectively)
for throughput verification.
---------------------------------------------------------
Title: In memoriam: Hugo van Woerden (1926 - 2020)
Authors: Bettonvil, Felix
2020JIMO...48..163B Altcode:
On September 4, 2020, Prof. Dr. Hugo van Woerden passed away at the
age of 94 after a short illness. Hugo was both an amateur and famous
professional astronomer. In 1946, he was one of the founders of the
Meteor Section of the Royal Netherlands Association for Meteorology
and Astronomy (KNVWS Werkgroep Meteoren), and invented the use of star
fields to determine the observer's limiting magnitude. Van Woerden
was professor in radio astronomy, made famous by his work at the
Kapteyn Institute in Groningen and among the first practicing radio
astronomy in the Netherlands, and carried out important research with
the Dwingeloo and Westerbork radio telescopes.
---------------------------------------------------------
Title: Warm calibration unit of the mid-infrared E-ELT instrument
METIS: overview and current status of the project
Authors: Rutowska, Monika; Sharma, Tarun; Wiest, Michael; Graf, Sabine;
Straubmeier, Christian; Rost, Steffen; Labadie, Lucas; Eckart, Andreas;
Burtscher, Leonard; Agócs, Tibor; Lesman, Dirk; Stuik, Remko; Glauser,
Adrian; Brandl, Bernhard; Bettonvil, Felix
2020SPIE11447E..2TR Altcode:
The warm calibration unit (WCU) is one subsystem of the future METIS
instrument on the European Extremely Large Telescope (E-ELT). Operating
at daytime temperature, the WCU is mounted above the main cryostat
of METIS and will be employed as calibration reference for science
observations, as well as for verification and alignment purposes during
the AIT phase. The WCU is designed and constructed at the University of
Cologne, partner in the METIS consortium. The WCU, together with the
full METIS instrument, went recently through a successful preliminary
design review (PDR) phase at ESO and is entering now the Phase C of the
project. In this paper, we present the current status of the WCU and
summarize the mostly mechanical and optical engineering work. We adopted
a hexapod unit to interface with the METIS cryostat and a CFRP-based
optical bench to optimally cope with alignment flexure. We develop
the case for fiber-fed laser sources feeding the integrating sphere
for spectral calibration of the LM-Spectrograph of METIS. We detail
the activity foreseen for Phase C including the optical tolerances
analysis, the eigenfrequency and earthquake analysis and a preparation
of the sub-system MAIT work, finishing the paper with a short overview
of the WCU future plans.
---------------------------------------------------------
Title: Another Daylight Fireball over The Netherlands: The event of
2020 August 25
Authors: Bettonvil, Felix
2020JIMO...48..185B Altcode:
In recent years, we notice that more daylight fireballs are
reported. This initiated the development and installation of a dedicated
daylight all sky camera, aiming at capturing such events with good
quality. On the 25th of August 2020, yet another daylight fireball
appeared, around sunset, which was captured by the daylight camera. 240
fireball reports were received. We report on the results and analysis.
---------------------------------------------------------
Title: In memoriam Hugo van Woerden (1926 - 2020)
Authors: Bettonvil, Felix
2020eMetN...5..362B Altcode:
On September 4, 2020, Prof. Dr. Hugo van Woerden, after a short
illness, passed away at the age of 94. Hugo was both amateur and famous
professional astronomer, and one of the founders of the Meteor Section
of the Royal Dutch Association for Astronomy and Meteorology (KNVWS
Werkgroep Meteoren), in 1946, and inventor of the use of star fields
to determine the observer's limiting magnitude. Hugo van Woerden was
professor in radio astronomy at the Kapteyn Institute in Groningen
and among the first practicing radio astronomy in the Netherlands,
and carried out important research with the Dwingeloo and Westerbork
radio telescopes.
---------------------------------------------------------
Title: Detection of polarization neutral points in observations of the
combined corona and sky during the 21 August 2017 total solar eclipse
Authors: Snik, Frans; Bos, Steven P.; Brackenhoff, Stefanie A.;
Doelman, David S.; Por, Emiel H.; Bettonvil, Felix; Rodenhuis, Michiel;
Vorobiev, Dmitry; Eshelman, Laura M.; Shaw, Joseph A.
2020ApOpt..59F..71S Altcode: 2020arXiv200712482S
We report the results of polarimetric observations of the total solar
eclipse of 21 August 2017 from Rexburg, Idaho (USA). We use three
synchronized DSLR cameras with polarization filters oriented at 0°,
60°, and 120° to provide high-dynamic-range RGB polarization images
of the corona and surrounding sky. We measure tangential coronal
polarization and vertical sky polarization, both as expected. These
observations provide detailed detections of polarization neutral points
above and below the eclipsed Sun where the coronal polarization is
canceled by the sky polarization. We name these special polarization
neutral points after Minnaert and Van de Hulst.
---------------------------------------------------------
Title: Conference summary
Authors: Bettonvil, Felix
2020pimo.conf..158B Altcode:
Without doubt we can say that the 2019 IMC in Bollmansruh was once
again a great success. During the four days a plethora of topics was
presented, covering the wide scope of meteor science well. Instrumental
development, software tools, observational results, analysis, modelling
as well as public awareness was discussed, on an exciting conference
location and in a great atmosphere with participants of all ages,
both amateur and professional. Great achievements have been in the
realization of very large camera networks, the availability of handy
software tools and cross fertilization between disciplines and areas of
interest. Meteor science is clearly broadening, making it very exciting.
---------------------------------------------------------
Title: Daytime fireball capturing
Authors: Bettonvil, Felix
2020pimo.conf..135B Altcode:
Traditionally, fireball patrol cameras are constructed to capture
fireballs during night time. Fireballs nonetheless – and in particular
meteorite dropping ones – do not only appear at night time: there
a various examples of great fireballs that did appear at twilight
or even daytime. In an attempt to have also daytime coverage I will
present some recent test work on a panoramic surveillance cam.
---------------------------------------------------------
Title: Status of the mid-IR ELT imager and spectrograph (METIS)
Authors: Brandl, Bernhard R.; Absil, Olivier; Agócs, Tibor; Baccichet,
Nicola; Bertram, Thomas; Bettonvil, Felix; van Boekel, Roy; Burtscher,
Leonard; van Dishoeck, Ewine; Feldt, Markus; Garcia, Paulo J. V.;
Glasse, Alistair; Glauser, Adrian; Güdel, Manuel; Haupt, Christoph;
Kenworthy, Matthew A.; Labadie, Lucas; Laun, Werner; Lesman, Dirk;
Pantin, Eric; Quanz, Sascha P.; Snellen, Ignas; Siebenmorgen, Ralf;
van Winckel, Hans
2018SPIE10702E..1UB Altcode:
The Mid-Infrared ELT Imager and Spectrograph (METIS) is one of three
first light instruments on the ELT. It will provide high-contrast
imaging and medium resolution, slit-spectroscopy from 3 - 19um, as
well as high resolution (R 100,000) integral field spectroscopy from
2.9-5.3µm. All modes observe at the diffraction limit of the ELT,
by means of adaptive optics, yielding angular resolutions of a few
tens of milliarcseconds. The range of METIS science is broad, from
Solar System objects to active galactic nuclei (AGN). We will present
an update on the main science drivers for METIS: circum-stellar disks
and exoplanets. The METIS project is now in full steam, approaching its
preliminary design review (PDR) in 2018. In this paper we will present
the current status of its optical, mechanical and thermal design as
well as operational aspects. We will also discuss the challenges of
building an instrument for the ELT, and the required technologies.
---------------------------------------------------------
Title: The calibration unit of the mid-infrared E-ELT instrument METIS
Authors: Baccichet, Nicola; Labadie, Lucas; Rost, Steffen; Straubmeier,
Christian; Wiest, Michael; Burtscher, Leonard; Agócs, Tibor; Jellema,
Willem; Roelfsema, Ronald; van Boekel, Roy; Glauser, Adrian; Brandl,
Bernhard; Bettonvil, Felix; Lynn, Jeff; Eckart, Andreas
2018SPIE10702E..91B Altcode:
We present the preliminary design of the calibration unit of the
future E-ELT instrument METIS. This independent subunit is mounted
externally to the main cryostat of METIS and will function both as
calibration reference for science observations, as well as verification
and alignment tool during the AIT phase. In this paper, we focus
on describing its preliminary layout and foreseen functionalities,
based on the performance requirements defined at system level and the
constraints imposed by warm IR background. We discuss the advantage of
employing an integrating sphere as common radiation emitter, leading
to a novel and versatile design, where the source's spatio-spectral
properties can be varied with high fidelity and repeatability. By
combining only few tuneable sources and mechanisms we show how a large
instrument such as METIS can be calibrated and tested, without the
need of a complex cold calibration unit.
---------------------------------------------------------
Title: The warm calibration unit of METIS: optical design and
principle of operation
Authors: Straubmeier, Christian; Baccichet, Nicola; Labadie, Lucas;
Rost, Steffen; Wiest, Michael; Eckart, Andreas; Brandl, Bernhard;
Agócs, Tibor; Roelfsema, Ronald; Lynn, Jeffrey; Bettonvil, Felix
2018SPIE10702E..8PS Altcode:
METIS, a mid-infrared imager and spectrograph for the wavelength
range 2.9-19μm (astronomical L-, M-, N- and Q-band), will be one of
the first three science instruments at the European Extremely Large
Telescope (E-ELT). It will provide diffraction limited imaging,
coronagraphy, high resolution integral field spectroscopy and low
and medium resolution slit spectroscopy. Within the international
METIS consortium, the 1st Institute of Physics of the University
of Cologne in Germany is responsible for the design, manufacturing,
integration and qualification of the Warm Calibration Unit (WCU) of
the instrument. The WCU will be a self-contained unit operating at
ambient temperature outside of the voluminous METIS dewar, feeding a
variety of optical calibration and alignment signals into the optical
path of METIS. The functionalities of the WCU will be used for routine
daily daytime calibrations after astronomical observing nights and
verification of the internal alignment of METIS during assembly,
integration and verification (AIV). In this contribution we present
the preliminary optical design and principle of operation of the WCU
in its current state of the preliminary design phase of METIS.
---------------------------------------------------------
Title: The installation and ongoing commissioning of the MATISSE
mid-infrared interferometer at the ESO Very Large Telescope
Observatory
Authors: Lopez, B.; Lagarde, S.; Matter, A.; Agocs, T.; Allouche, F.;
Antonelli, P.; Augereau, J. -C.; Bailet, C.; Berio, P.; Bettonvil, F.;
Beckmann, U.; van Boekel, R.; Bresson, Y.; Bristow, P.; Cruzalebes,
P.; Delbo, M.; Dominik, C.; Elswijk, E.; Fantei, Y.; Glindemann, A.;
Heininger, M.; Hofmann, K. -H.; Hogerheijde, M.; Hron, J.; Jaffe,
W.; Kroes, G.; Laun, W.; Lehmitz, M.; Meilland, A.; Meisenheimer,
K.; Millour, F.; Morel, S.; Neumann, U.; Pantin, E.; Petrov, R. G.;
Robbe-Dubois, S.; Schertl, D.; Schoeller, M.; Wolf, S.; Zins, G.;
Henning, T.; Stee, Ph.; Weigelt, G.
2018SPIE10701E..0ZL Altcode:
MATISSE is the second-generation mid-infrared spectrograph and imager
for the Very Large Telescope Interferometer (VLTI) at Paranal. This
new interferometric instrument will allow significant advances in
various fundamental research fields: studying the planet-forming
region of disks around young stellar objects, understanding the surface
structures and mass loss phenomena affecting evolved stars, and probing
the environments of black holes in active galactic nuclei. As a first
breakthrough, MATISSE will enlarge the spectral domain of current
optical interferometers by offering the L and M bands in addition to
the N band. This will open a wide wavelength domain, ranging from
2.8 to 13 μm, exploring angular scales as small as 3 mas (L band)
/ 10 mas (N band). As a second breakthrough, MATISSE will allow
mid-infrared imaging - closure-phase aperture-synthesis imaging -
with the four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the
VLTI. Moreover, MATISSE will offer a spectral resolution range from R
30 to R 5000. Here, we remind the concept, the instrumental design,
and the main features of MATISSE. We also describe the last months
of preparation, the status of the instrument, which was shipped to
Cerro Paranal on the site of the ESO Very Large Telescope in October
2017, and the expected schedule for the opening to the community. The
instrument is currently in its Commissioning phase. A complementary
dedicated article details the Commissioning results, which include
the first performance estimates on sky.
---------------------------------------------------------
Title: The MATISSE photometric slider: achieving sub-micrometer
reproducibility under cryogenic conditions
Authors: Bettonvil, Felix C. M.; Kroes, G.; Elswijk, E.; de Haan,
M.; ter Horst, R.; Kragt, J.; Navarro, R.; Schuil, M.; Tromp, T.
2018SPIE10706E..1AB Altcode:
MATISSE is the mid-infrared interferometric spectrograph and
imager for ESO's Very Large Telescope Interferometer (VLTI). A core
mechanism inside the Cold Optical bench is the photometric slider,
that enables the choice of observation with or without photometric
beams which is achieved by sliding in 4 mirrors or 4 beam splitters
into the four telescope beams. To achieve the stringent requirements
on beam precision -which asks for mounting pad differences of order of
1 micrometer- all optical components were mounted on a single body and
one lapped surface. Test results on the final instrument showed behavior
significantly outside specification suggesting contact point height
differences up to 6 micrometer. Also repeatability was non-compliant. We
will present the cause analysis, the suspected culprit, unsuspected
side effects and the implementation of the final solution which lead
to a photometric slider well within specification.
---------------------------------------------------------
Title: MATISSE: performance in laboratory, results of AIV in Paranal,
and first results on sky
Authors: Robbe-Dubois, S.; Lagarde, S.; Antonelli, P.; Lopez, B.;
Allouche, F.; Bailet, C.; Berio, Ph.; Bresson, Y.; Clausse, J. -M.;
Cruzalèbes, P.; Fantei-Caujolle, Y.; Marcotto, A.; Matter, A.;
Meilland, A.; Millour, F.; Morel, S.; Petrov, R. G.; Rousseau, S.;
Soulain, A.; Zins, G.; Lehmitz, M.; Laun, W.; Adler, T.; Klein, R.;
Maurer, T.; Bettonvil, F.; Eldswick, E.; Beckmann, U.; Heininger,
M.; Bristow, P.; Glindemann, A.; Hubin, N.; Jochum, L.; Rivinus,
Th.; Schoeller, M.; Beltran, J.; Bourget, P.; Gallenne, A.; Guerlet,
Th.; Haubois, X.; Ives, D.; Jakob, G.; Meister, A.; Riquelme, M.;
Schuhler, N.; Stephan, C.; Toledo, P.; Tristam, K.; Woillez, J.;
Neumann, U.; Chelli, A.; Guitton, F.; Meisenheimer, K.; Pichon, B.;
Spang, A.; Varga, J.; Henning, Th.; Jaffe, W.; Pasquini, L.; Stee,
Ph.; Weigelt, G.
2018SPIE10701E..0HR Altcode:
MATISSE (Multi AperTure mid-Infrared SpectroScopic Experiment) is the
spectro-interferometer for the VLTI of the European Southern Observatory
(ESO), operating in the L-, M- and N- spectral bands, and combining
up to four beams from the unit or the auxiliary telescopes (UTs or
ATs). MATISSE will offer new breakthroughs in the study of circumstellar
environments by allowing the mapping of the material distribution,
the gas and essentially the dust. The instrument consists in a warm
optical system (WOP) accepting four beams from the VLTI and relaying
them after a spectral splitting to cold optical benches (COB) located in
two separate cryostats, one in L-M- band, and one in N-band. The test
plan of the complete instrument has been conducted at the Observatoire
de la Côte d'Azur in order to confirm the compliance of the performance
with the high-level requirements. MATISSE has successfully passed the
Preliminary Acceptance in Europe the 12th September 2017. Following
this result, ESO gave approval for the instrument to be shipped to
Paranal. The Alignment, Integration and Verification phase was conducted
until end of February 2018, at the end of which first observations on
sky have been performed to test the operations with the VLTI and to
obtain first stellar light. The two first runs of the commissioning
followed, respectively in March and in May 2018. It has the goal to
optimize the MATISSE-VLTI communication, the acquisition procedures
and the interface parameters. The observations were performed on
bright L-M- and N- stars, with four ATs located on short baselines
and UTs. The limit magnitudes will be deduced. This paper reports on
the performance of the instrument measured in laboratory (results of
test plan in Nice and AIV in Paranal) in terms of spectral coverage,
dispersion laws and spectral resolutions, and transfer function
analysis: instrumental contrast, visibility accuracy, accuracy of
the differential phase, of the closure-phase and of the differential
visibility. It also provides results of the first tests on sky and
the planning of the on-going commissioning.
---------------------------------------------------------
Title: The Mid-IR ELT Imager and Spectrograph (METIS) and its Science
Goals in the Context of AKARI
Authors: Brandl, Bernhard R.; Quanz, Sascha; Snellen, Ignas; van
Dishoeck, Ewine; Pontoppidan, Klaus; Le Floch, Emeric; Bettonvil,
Felix; van Boekel, Roy; Glauser, Adrian; Hurtado, Norma
2018cwla.conf...41B Altcode:
The Mid-infrared ELT Imager and Spectrograph (METIS) is one the first
three scientific instruments on ESO's Extremely Large Telescope
(ELT). At the time of anticipated first light in 2025, METIS
will provide diffraction limited imaging, coronagraphy and medium
resolution slit spectroscopy in the 3-19 micrometers range, as well
as high resolution (R approximately equals to 100, 000) integral field
spectroscopy from 2.9-5.3 micrometers. The unique combination of these
observing capabilities with an angular resolution of 0.020 sec, and
the sensitivity provided by a 40m aperture, make METIS a very powerful
tool to study the infrared sky - from objects in our Solar system,
the Galactic center, brown dwarfs, evolved stars, and massive stellar
clusters to active galactic nuclei (AGN), local starbursts, transient
events, and luminous infrared galaxies at intermediate redshifts. Its
main scientific focus, however, will be on the study of proto-planetary
disks and exoplanets. In this paper, we describe the instrument concept
and performance. We discuss the scientific performance of METIS with
respect to AKARI, and elaborate on the relevance of the AKARI archive
with respect to the METIS observing program.
---------------------------------------------------------
Title: Meteorite detection with airborne support—a study case
Authors: Zender, Joe; Rudawska, Regina; Koschny, Detlef; Drolshagen,
Gerhard; Netjes, Gert-Jan; Bosch, Mirko; Bijl, Rik; Crevecoeur, Rob;
Bettonvil, Felix
2018pimo.conf..145Z Altcode:
The search for meteorites is a cumbersome and tough activity. After
having instrumental evidence, i.e., the detection of fireballs in
one of the existing fireball networks and the computation of the
potential landing site area, a group of enthousiasts often spends
days in the search for meteorites. This study analyses if the use of
airborne cameras can support the meteorite search. A set of 11 test
meteorites was distributed on two different kind of surface areas:
a grass field and a harvested wheat field. A high-resolution camera
mounted on a drone acquired images at 60 meters altitude. The images
were post-processed to identify the meteorites. The algorithm detected
at least half of the meteorites.
---------------------------------------------------------
Title: Preliminary optical design for the common fore optics of METIS
Authors: Agócs, Tibor; Brandl, Bernhard R.; Jager, Rieks; Bettonvil,
Felix; Aitink-Kroes, Gabby; Venema, Lars; Kenworthy, Matthew; Absil,
Olivier; Bertram, Thomas
2016SPIE.9908E..9QA Altcode:
METIS is the Mid-infrared E-ELT Imager and Spectrograph, which will
provide outstanding observing capabilities, focusing on high angular
and spectral resolution. It consists of two diffraction-limited
imagers operating in the LM and NQ bands respectively and an
IFU fed diffraction-limited high-resolution (R=100,000) LM band
spectrograph. These science subsystems are preceded by the common fore
optics (CFO), which provides the following essential functionalities:
calibration, chopping, image de-rotation, thermal background and stray
light reduction. We show the evolution of the CFO optical design from
the conceptual design to the preliminary optical design, detail the
optimization steps and discuss the necessary trade-offs.
---------------------------------------------------------
Title: MATISSE: alignment, integration, and test phase first results
Authors: Allouche, F.; Robbe-Dubois, S.; Lagarde, S.; Cruzalèbes,
P.; Antonelli, P.; Bresson, Y.; Fantei-Caujolle, Y.; Marcotto, A.;
Morel, S.; Beckmann, U.; Bettonvil, F.; Berio, Ph.; Heininger, M.;
Lehmitz, M.; Agocs, T.; Brast, R.; Elswijk, E.; Ives, D.; Meixner,
K.; Laun, W.; Mellein, M.; Neumann, U.; Bailet, C.; Clausse, J. -M.;
Matter, A.; Meilland, A.; Millour, F.; Petrov, R. G.; Accardo, M.;
Bristow, P.; Frahm, R.; Glindemann, A.; Gonzáles Herrera, J. -C.;
Lizon, J. -L.; Schöller, M.; Graser, U.; Jaffe, W.; Lopez, B.
2016SPIE.9907E..0CA Altcode:
MATISSE (Multi AperTure mid-Infrared SpectroScopic Experiment) is
the spectro-interferometer for the VLTI of the European Southern
Observatory, operating in near and mid-infrared, and combining up to
four beams from the unit or the auxiliary telescopes. MATISSE will offer
new breakthroughs in the study of circumstellar environments by allowing
the multispectral mapping of the material distribution, the gas and
essentially the dust. The instrument consists in a warm optical system
(WOP) accepting four optical beams and relaying them after a dichroic
splitting (for the L and M- and N- spectral bands) to cold optical
benches (COB) located in two separate cryostats. The Observatoire de
la Côte d'Azur is in charge of the WOP providing the spectral band
separation, optical path equalization and modulation, pupil positioning,
beam anamorphosis, beam commutation, and calibration. NOVA-ASTRON is in
charge of the COB providing the functions of beam selection, reduction
of thermal background emission, spatial filtering, pupil transfer,
photometry and interferometry splitting, additional beam anamorphosis,
spectral filtering, polarization selection, image dispersion, and image
combination. The Max Planck Institut für Radio Astronomie is in charge
of the operation and performance validation of the two detectors,
a HAWAII-2RG from Teledyne for the L- and M- bands and a Raytheon
AQUARIUS for the N-band. Both detectors are provided by ESO. The Max
Planck Institut für Astronomie is in charge of the electronics and the
cryostats for which the requirements on space limitations and vibration
stability resulted on very specific and stringent decisions on the
design. The integration and test of the COB: the two cryogenic systems,
including the cold benches and the detectors, have been conducted
at MPIA in parallel with the integration of the WOP at OCA. At the
end of 2014, the complete instrument was integrated at OCA. Following
this integration, a period of interface and alignment between the COB
and the WOP took place resulting in the first interference fringes
in the L-band during summer 2015 and the first interference fringes
in the N-ban in March 2016. After a period of optimization of both
the instrument reliability and the environmental working conditions,
the test plan is presently being conducted in order to evaluate the
complete performance of the instrument and its compliance with the
high-level requirements. The present paper gives the first results of
the alignment, integration and test phase of the MATISSE instrument.
---------------------------------------------------------
Title: An overview of the mid-infrared spectro-interferometer MATISSE:
science, concept, and current status
Authors: Matter, A.; Lopez, B.; Antonelli, P.; Lehmitz, M.; Bettonvil,
F.; Beckmann, U.; Lagarde, S.; Jaffe, W.; Petrov, R.; Berio, P.;
Millour, F.; Robbe-Dubois, S.; Glindemann, A.; Bristow, P.; Schoeller,
M.; Lanz, T.; Henning, T.; Weigelt, G.; Heininger, M.; Morel, S.;
Cruzalebes, P.; Meisenheimer, K.; Hofferbert, R.; Wolf, S.; Bresson,
Y.; Agocs, T.; Allouche, F.; Augereau, J. -C.; Avila, G.; Bailet, C.;
Behrend, J.; van Belle, G.; Berger, J. -P.; van Boekel, R.; Bourget,
P.; Brast, R.; Clausse, J. -M.; Connot, C.; Conzelmann, R.; Csepany,
G.; Danchi, W. C.; Delbo, M.; Dominik, C.; van Duin, A.; Elswijk, E.;
Fantei, Y.; Finger, G.; Gabasch, A.; Gonté, F.; Graser, U.; Guitton,
F.; Guniat, S.; De Haan, M.; Haguenauer, P.; Hanenburg, H.; Hofmann,
K. -H.; Hogerheijde, M.; ter Horst, R.; Hron, J.; Hummel, C.; Isderda,
J.; Ives, D.; Jakob, G.; Jasko, A.; Jolley, P.; Kiraly, S.; Kragt,
J.; Kroener, T.; Kroes, G.; Kuindersma, S.; Labadie, L.; Laun, W.;
Leinert, C.; Lizon, J. -L.; Lucuix, C.; Marcotto, A.; Martinache,
F.; Martinot-Lagarde, G.; Mauclert, N.; Mehrgan, L.; Meilland, A.;
Mellein, M.; Menardi, S.; Merand, A.; Neumann, U.; Nussbaum, E.;
Ottogalli, S.; Palsa, R.; Panduro, J.; Pantin, E.; Percheron, I.;
Phan Duc, T.; Pott, J. -U.; Pozna, E.; Roelfsema, R.; Rupprecht, G.;
Schertl, D.; Schmidt, C.; Schuil, M.; Spang, A.; Stegmeier, J.; Tromp,
N.; Vakili, F.; Vannier, M.; Wagner, K.; Venema, L.; Woillez, J.
2016SPIE.9907E..0AM Altcode: 2016arXiv160802350M
MATISSE is the second-generation mid-infrared spectrograph and imager
for the Very Large Telescope Interferometer (VLTI) at Paranal. This
new interferometric instrument will allow significant advances by
opening new avenues in various fundamental research fields: studying
the planet-forming region of disks around young stellar objects,
understanding the surface structures and mass loss phenomena affecting
evolved stars, and probing the environments of black holes in active
galactic nuclei. As a first breakthrough, MATISSE will enlarge the
spectral domain of current optical interferometers by offering the L
and M bands in addition to the N band. This will open a wide wavelength
domain, ranging from 2.8 to 13 μm, exploring angular scales as small
as 3 mas (L band) / 10 mas (N band). As a second breakthrough, MATISSE
will allow mid-infrared imaging - closure-phase aperture-synthesis
imaging - with up to four Unit Telescopes (UT) or Auxiliary Telescopes
(AT) of the VLTI. Moreover, MATISSE will offer a spectral resolution
range from R ∼ 30 to R ∼ 5000. Here, we present one of the main
science objectives, the study of protoplanetary disks, that has driven
the instrument design and motivated several VLTI upgrades (GRA4MAT
and NAOMI). We introduce the physical concept of MATISSE including
a description of the signal on the detectors and an evaluation of
the expected performances. We also discuss the current status of
the MATISSE instrument, which is entering its testing phase, and the
foreseen schedule for the next two years that will lead to the first
light at Paranal.
---------------------------------------------------------
Title: Status of the mid-infrared E-ELT imager and spectrograph METIS
Authors: Brandl, Bernhard R.; Agócs, Tibor; Aitink-Kroes, Gabby;
Bertram, Thomas; Bettonvil, Felix; van Boekel, Roy; Boulade, Olivier;
Feldt, Markus; Glasse, Alistair; Glauser, Adrian; Güdel, Manuel;
Hurtado, Norma; Jager, Rieks; Kenworthy, Matthew A.; Mach, Michael;
Meisner, Jeff; Meyer, Michael; Pantin, Eric; Quanz, Sascha; Schmid,
Hans Martin; Stuik, Remko; Veninga, Auke; Waelkens, Christoffel
2016SPIE.9908E..20B Altcode:
METIS is one the first three instruments on the E-ELT. Apart from
diffraction limited imaging, METIS will provide coronagraphy and medium
resolution slit spectroscopy over the 3 - 19μm range, as well as high
resolution (R 100,000) integral field spectroscopy from 2.9 - 5.3μm,
including a mode with extended instantaneous wavelength coverage. The
unique combination of these observing capabilities, makes METIS the
ideal instrument for the study of circumstellar disks and exoplanets,
among many other science areas. In this paper we provide an update of
the relevant science drivers, the METIS observing modes, the status
of the simulator and the data analysis. We discuss the preliminary
design of the optical system, which is driven by the need to calibrate
observations at thermal IR wavelengths on a six-mirror ELT. We present
the expected adaptive optics performance and the measures taken to
enable high contrast imaging. We describe the opto-mechanical system,
the location of METIS on the Nasmyth instrument platform, and conclude
with an update on critical subsystem components, such as the immersed
grating and the focal plane detectors. In summary, the work on METIS
has taken off well and is on track for first light in 2025.
---------------------------------------------------------
Title: MeerLICHT and BlackGEM: custom-built telescopes to detect
faint optical transients
Authors: Bloemen, Steven; Groot, Paul; Woudt, Patrick; Klein Wolt,
Marc; McBride, Vanessa; Nelemans, Gijs; Körding, Elmar; Pretorius,
Margaretha L.; Roelfsema, Ronald; Bettonvil, Felix; Balster, Harry;
Bakker, Roy; Dolron, Peter; van Elteren, Arjen; Elswijk, Eddy; Engels,
Arno; Fender, Rob; Fokker, Marc; de Haan, Menno; Hagoort, Klaas;
de Hoog, Jasper; ter Horst, Rik; van der Kevie, Giel; Kozłowski,
Stanisław; Kragt, Jan; Lech, Grzegorz; Le Poole, Rudolf; Lesman,
Dirk; Morren, Johan; Navarro, Ramon; Paalberends, Willem-Jelle;
Paterson, Kerry; Pawłaszek, Rafal; Pessemier, Wim; Raskin, Gert;
Rutten, Harrie; Scheers, Bart; Schuil, Menno; Sybilski, Piotr W.
2016SPIE.9906E..64B Altcode:
We present the MeerLICHT and BlackGEM telescopes, which are wide-field
optical telescopes that are currently being built to study transient
phenomena, gravitational wave counterparts and variable stars. The
telescopes have 65 cm primary mirrors and a 2.7 square degree
field-of-view. The MeerLICHT and BlackGEM projects have different
science goals, but will use identical telescopes. The first telescope,
MeerLICHT, will be commissioned at Sutherland (South Africa) in the
first quarter of 2017. It will co-point with MeerKAT to collect optical
data commensurate with the radio observations. After careful analysis
of MeerLICHT's performance, three telescopes of the same type will
be commissioned in La Silla (Chile) in 2018 to form phase I of the
BlackGEM array. BlackGEM aims at detecting and characterizing optical
counterparts of gravitational wave events detected by Advanced LIGO
and Virgo. In this contribution we present an overview of the science
goals, the design and the status of the two projects.
---------------------------------------------------------
Title: FAME: freeform active mirror experiment
Authors: Aitink-Kroes, Gabby; Agócs, Tibor; Miller, Chris; Black,
Martin; Farkas, Szigfrid; Lemared, Sabri; Bettonvil, Felix; Montgomery,
David; Marcos, Michel; Jaskó, Attila; van Duffelen, Farian; Challita,
Zalpha; Fok, Sandy; Kiaeerad, Fatemeh; Hugot, Emmanuel; Schnetler,
Hermine; Venema, Lars
2016SPIE.9912E..1IA Altcode:
FAME is a four-year project and part of the OPTICON/FP7 program that
is aimed at providing a breakthrough component for future compact,
wide field, high resolution imagers or spectrographs, based on both
Freeform technology, and the flexibility and versatility of active
systems. Due to the opening of a new parameter space in optical design,
Freeform Optics are a revolution in imaging systems for a broad
range of applications from high tech cameras to astronomy, via earth
observation systems, drones and defense. Freeform mirrors are defined
by a non-rotational symmetry of the surface shape, and the fact that
the surface shape cannot be simply described by conicoids extensions,
or off-axis conicoids. An extreme freeform surface is a significantly
challenging optical surface, especially for UV/VIS/NIR diffraction
limited instruments. The aim of the FAME effort is to use an extreme
freeform mirror with standard optics in order to propose an integrated
system solution for use in future instruments. The work done so far
concentrated on identification of compact, fast, widefield optical
designs working in the visible, with diffraction limited performance;
optimization of the number of required actuators and their layout; the
design of an active array to manipulate the face sheet, as well as the
actuator design. In this paper we present the status of the demonstrator
development, with focus on the different building blocks: an extreme
freeform thin face sheet, the active array, a highly controllable
thermal actuator array, and the metrology and control system.
---------------------------------------------------------
Title: Development and final design of FAME active array
Authors: Farkas, Szigfrid; Agócs, Tibor; Aitink-Kroes, Gabby;
Bettonvil, Felix; Black, Martin; Hugot, Emmanuel; Jaskó, Attila;
Miller, Chris; Schnetler, Hermine; van Duffelen, Farian; Venema, Lars
2016SPIE.9912E..09F Altcode:
FAME (Freeform Active Mirror Experiment - part of the FP7 OPTICON/FP7
development programme) intends to demonstrate the huge potential
of active mirrors and freeform optical surfaces. Freeform active
surfaces can help to address the new challenges of next generation
astronomical instruments, which are bigger, more complex and have
tighter specifications than their predecessors. The FAME design
consists of a pre-formed, deformable thin mirror sheet with an active
support system. The thin face sheet provides a close to final surface
shape with very high surface quality. The active array provides the
support, and through actuation, the control to achieve final surface
shape accuracy. In this paper the development path, trade-offs and
demonstrator design of the FAME active array is presented. The key
step in the development process of the active array is the design
of the mechanical structure and especially the optimization of the
actuation node positions, where the actuator force is transmitted to
the thin mirror sheet. This is crucial for the final performance of
the mirror where the aim is to achieve an accurate surface shape,
with low residual (high order) errors using the minimum number of
actuators. These activities are based on the coupling of optical
and mechanical engineering, using analytical and numerical methods,
which results in an active array with optimized node positions and
surface shape.
---------------------------------------------------------
Title: The BlackGEM array in search of black hole mergers: integrated
performance modelling
Authors: Roelfsema, Ronald; Klein Wolt, Marc; Bloemen, Steven; Groot,
Paul; Bettonvil, Felix; Balster, Harry; Dolron, Peter; van Elteren,
Arjen; Engels, Arno; de Haan, Menno; ter Horst, Rik; Kragt, Jan;
Navarro, Ramon; Nelemans, Gijs; Paalberends, Willem Jelle; Pal,
Sari; Raskin, Gert; Rutten, Harrie; Scheers, Bart; Schuil, Menno;
Sybilski, Piotr
2016SPIE10012E..06R Altcode:
The Radboud University Nijmegen in collaboration with the NOVA Optical
Infrared Instrumentation group at ASTRON is currently leading the
development and realization of the BlackGEM observing facility. The
BlackGEM science team aims to be the first to catch the optical
counterpart of a gravitational wave event. The BlackGEM project will
put an array of three medium-sized optical telescopes at the La Silla
site of the European Southern Observatory in Chile. It is uniquely
equipped to achieve a combination of wide-field and high sensitivity
through its array-like approach. Each BlackGEM unit telescope is a
modified Dall-Kirkham-type telescope consisting of a 65cm primary
mirror, a 21cm spherical secondary mirror and a triplet corrector
lens. The spatial resolution on the sky will be 0.56 asec/pixel and
the total field-of-view per telescope is 2.7 square degrees. The main
requirement is to achieve a 5-sigma sensitivity of 23rd magnitude
within a 5-minute exposure under 15 m/s wind gust conditions. This
demands a very stable optical system with tight control of all the
error contributions. This has been realized with a spreadsheet based
integrated instrument model. The model contains all relevant telescope
instrument parameters and environmental conditions. The spreadsheet is
partly used for performance calculations and partly used to combine
and integrate the output from several other sources. The spreadsheet
model calculates the overall performance based on an Exposure Time
Calculator using the Noise Equivalent Area metric (NEA). The NEA is
further budgeted over 7 main High Level Requirements. The spreadsheet
model is coupled to 1) a ZEMAX telescope optical model 2) a telescope
FEM analysis to predict the optomechanical response under various
gravity, temperature and wind load conditions, 3) a Matlab Simulink
thermal model to predict the transient temperature behaviour of the
most important telescope elements and 4) a Matlab Simulink control
model to predict the performance of the active M2 mirror. All outputs
are collected in a system performance budget that readily shows the
compliance with the main High Level Requirements.
---------------------------------------------------------
Title: Foreword
Authors: Bettonvil, F.
2016pimo.conf....6B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Accurate Geminid velocities with CHIPOlAtA
Authors: Bettonvil, F.
2016pimo.conf...31B Altcode:
For several years, the high-resolution photographic camera CHIPOlAtA
has been used to acquire precise orbits for Geminid and Perseid meteor
shower members. In this paper I analyze the first set of data obtained
during the Geminids 2014.
---------------------------------------------------------
Title: Program of the 35th International Meteor Conference, Egmond ,
2 - 5 June, 2016
Authors: Bettonvil, F.
2016pimo.conf...13B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: High resolution orbits of Perseids and Geminids with CHIPOlAtA
Authors: Bettonvil, F.
2015pimo.conf...78B Altcode:
This paper focuses on the first results of the high-resolution camera
project CHIPOlAtA that aims at measuring velocity with high accuracy,
based on a setup with a fast liquid crystal optical chopper. So
far three campaigns were carried out during the Perseid and Geminid
maxima. The preliminary results, data reduction, a sensitivity analysis
and the development of a data reduction pipeline are discussed.
---------------------------------------------------------
Title: HHEBBES! All sky camera system: status update
Authors: Bettonvil, F.
2015pimo.conf..138B Altcode:
A status update is given of the HHEBBES! All sky camera
system. HHEBBES!, an automatic camera for capturing bright meteor
trails, is based on a DSLR camera and a Liquid Crystal chopper for
measuring the angular velocity. Purpose of the system is to a) recover
meteorites; b) identify origin/parental bodies. In 2015, two new cameras
were rolled out: BINGO! -alike HHEBBES! also in The Netherlands-,
and POgLED, in Serbia. BINGO! is a first camera equipped with a longer
focal length fisheye lens, to further increase the accuracy. Several
minor improvements have been done and the data reduction pipeline was
used for processing two prominent Dutch fireballs.
---------------------------------------------------------
Title: De fraaie vuurbol van 19 oktober 2014
Authors: Miskotte, Koen; Langbroek, Marco; Bettonvil, Felix;
Johannink, Carl
2014eRad...10...59M Altcode:
Overview of all available observations and analyzes of the fireball
of October 19, 2014.
---------------------------------------------------------
Title: An Overview of the MATISSE Instrument — Science, Concept
and Current Status
Authors: Lopez, B.; Lagarde, S.; Jaffe, W.; Petrov, R.; Schöller,
M.; Antonelli, P.; Beckmann, U.; Berio, P.; Bettonvil, F.;
Glindemann, A.; Gonzalez, J. -C.; Graser, U.; Hofmann, K. -H.;
Millour, F.; Robbe-Dubois, S.; Venema, L.; Wolf, S.; Henning, T.;
Lanz, T.; Weigelt, G.; Agocs, T.; Bailet, C.; Bresson, Y.; Bristow,
P.; Dugué, M.; Heininger, M.; Kroes, G.; Laun, W.; Lehmitz, M.;
Neumann, U.; Augereau, J. -C.; Avila, G.; Behrend, J.; van Belle, G.;
Berger, J. -P.; van Boekel, R.; Bonhomme, S.; Bourget, P.; Brast,
R.; Clausse, J. -M.; Connot, C.; Conzelmann, R.; Cruzalèbes, P.;
Csepany, G.; Danchi, W.; Delbo, M.; Delplancke, F.; Dominik, C.;
van Duin, A.; Elswijk, E.; Fantei, Y.; Finger, G.; Gabasch, A.; Gay,
J.; Girard, P.; Girault, V.; Gitton, P.; Glazenborg, A.; Gonté, F.;
Guitton, F.; Guniat, S.; De Haan, M.; Haguenauer, P.; Hanenburg, H.;
Hogerheijde, M.; ter Horst, R.; Hron, J.; Hugues, Y.; Hummel, C.;
Idserda, J.; Ives, D.; Jakob, G.; Jasko, A.; Jolley, P.; Kiraly,
S.; Köhler, R.; Kragt, J.; Kroener, T.; Kuindersma, S.; Labadie,
L.; Leinert, C.; Le Poole, R.; Lizon, J. -L.; Lucuix, C.; Marcotto,
A.; Martinache, F.; Martinot-Lagarde, G.; Mathar, R.; Matter, A.;
Mauclert, N.; Mehrgan, L.; Meilland, A.; Meisenheimer, K.; Meisner,
J.; Mellein, M.; Menardi, S.; Menut, J. -L.; Merand, A.; Morel, S.;
Mosoni, L.; Navarro, R.; Nussbaum, E.; Ottogalli, S.; Palsa, R.;
Panduro, J.; Pantin, E.; Parra, T.; Percheron, I.; Duc, T. P.; Pott,
J. -U.; Pozna, E.; Przygodda, F.; Rabbia, Y.; Richichi, A.; Rigal, F.;
Roelfsema, R.; Rupprecht, G.; Schertl, D.; Schmidt, C.; Schuhler, N.;
Schuil, M.; Spang, A.; Stegmeier, J.; Thiam, L.; Tromp, N.; Vakili,
F.; Vannier, M.; Wagner, K.; Woillez, J.
2014Msngr.157....5L Altcode:
MATISSE, a second generation Very Large Telescope Interferometer (VLTI)
instrument, is a combined imager and spectrograph for interferometry
in the 3-5 μm region (L- and M-bands) and the 8-13 μm window
(N-band). MATISSE builds on the experience gained with the VLTI's
first generation instruments. It employs multi-axial beam combination
while also providing wavelength differential visibility and phase,
and closure-phase aperture-synthesis imaging at a range of spectral
resolutions. MATISSE is designed for a broad range of science goals,
and its potential for studies of the discs around young stars and
active galactic nuclei are highlighted. The instrument concept and
operating modes are described; construction is in progress towards
installation at the VLTI in 2016.
---------------------------------------------------------
Title: Complexity in the MATISSE cold optics: a risk or a tool?
Authors: Tromp, Niels; Bettonvil, Felix; Aitink-Kroes, Gabby; Agócs,
Tibor; Navarro, Ramón
2014SPIE.9150E..1DT Altcode:
MATISSE (Multi AperTure mid-Infrared SpectroScopic Experiment) will
be a mid-infrared spectro-interferometer combining the beams of up
to four telescopes of the European Southern Observatory Very Large
Telescope Interferometer (ESO VLTI), providing phase closure and image
reconstruction. MATISSE will produce interferometric spectra in the LM
and N band (2.8 to 13 micron). Building the cryogenic interferometer
section of an instrument like MATISSE is inherently complex. During the
preliminary design phase it became clear that this inherent complexity
should not be seen as a hurdle but rather a tool; to keep project
risks low it is vital to first comprehend the complexity and second to
distribute these complexities to areas of expertise, i.e. fields of low
risk. With this approach one prevents the typical reaction of either
steering away from complexity or digging narrow and deep to find only a
local solution. Complexity can be used to achieve the project goals with
a reduced overall project risk. For example two alternative options:
either a complex single structure with limited interfaces or an assembly
of many simpler parts with, in total, much more interfaces. Although
simpler in approach, the latter would be a burden on the overall
tolerance chain, assembly procedures, logistics & overall cost,
culminating in a higher overall risk to the project; the unintended
shift of complexity and risk to a later project phase. In addition,
this fragmentation would reduce the overall grip on the project and
would make it more difficult to identify showstoppers early on. And
solving these becomes exponentially more difficult in later project
stages. The integral multidisciplinary approach, earlier discussed in
"MATISSE cold optics opto-mechanical design" Proc. SPIE 7734, 77341S
(2010), enables optimal distribution of complexity and lowering of
overall project risk. This current proceeding presents the way in
which the high level of opto-mechanical complexity and risks were
distributed and dealt with during the MATISSE Cold Optics Bench
instrument development.
---------------------------------------------------------
Title: Remote and automatic small-scale observatories: experience
with an all-sky fireball patrol camera
Authors: Bettonvil, Felix C. M.
2014SPIE.9147E..3UB Altcode:
This paper describes the design of a remote, automatic all-sky
camera for capturing bright meteor trails based on a DSLR camera
combined with Liquid Crystal shutter technology for angular velocity
measurement. Design, performance and first results are discussed, as
well the up scaling towards a large autonomous network for accurate
fireball orbit determination and meteorite recovery.
---------------------------------------------------------
Title: MATISSE status report and science forecast
Authors: Lopez, B.; Lagarde, S.; Jaffe, W.; Petrov, R.; Schöller,
M.; Antonelli, P.; Beckman, U.; Bério, Ph.; Bettonvil, F.; Graser,
U.; Millour, F.; Robbe-Dubois, S.; Venema, L.; Wolf, S.; Bristow, P.;
Glindemann, A.; Gonzalez, J. -C.; Lanz, Th.; Henning, T.; Weigelt,
G.; Agócs, T.; Augereau, J. -C.; Ávila, G.; Bailet, C.; Behrend,
J.; Berger, J. -P.; von Boekel, Roy; Bonhomme, S.; Bourget, P.; Brast,
R.; Bresson, Y.; Clausse, J. M.; Chesneau, O.; Csépány, G.; Connot,
C.; Crida, A.; Danchi, W. C.; Delbo, M.; Delplancke, F.; Dominik, C.;
Dugué, M.; Elswijk, E.; Fanteï, Y.; Finger, G.; Gabasch, A.; Girard,
P.; Girault, V.; Gitton, P.; Glazenborg, A.; Gonté, F.; Guitton, F.;
Guniat, S.; De Haan, M.; Haguenauer, P.; Hanenburg, H.; Heininger, M.;
Hofmann, K. -H.; Hogerheijde, M.; ter Horst, R.; Hron, J.; Hughes, Y.;
Ives, D.; Jakob, G.; Jaskó, A.; Jolley, P.; Kragt, J.; Köhler, R.;
Kroener, T.; Kroes, G.; Labadie, L.; Laun, W.; Lehmitz, M.; Leinert,
Ch.; Lizon, J. L.; Lucuix, Ch.; Marcotto, A.; Martinache, F.; Matter,
A.; Martinot-Lagarde, G.; Mauclert, N.; Mehrgan, L.; Meilland, A.;
Mellein, M.; Ménardi, S.; Menut, J. L.; Meisenheimer, K.; Morel,
S.; Mosoni, L.; Navarro, R.; Neumann, U.; Nussbaum, E.; Ottogalli,
S.; Palsa, R.; Panduro, J.; Pantin, E.; Percheron, I.; Duc, T. Phan;
Pott, J. -U.; Pozna, Eszter; Przygodda, F.; Richichi, A.; Rigal,
F.; Rupprecht, G.; Schertl, D.; Stegmeier, J.; Thiam, L.; Tromp, N.;
Vannier, M.; Vakili, F.; van Belle, G.; Wagner, K.; Woillez, J.
2014SPIE.9146E..0ML Altcode:
MATISSE is the mid-infrared spectrograph and imager for the Very Large
Telescope Interferometer (VLTI) at Paranal. This second generation
interferometry instrument will open new avenues in the exploration
of our Universe. Mid-infrared interferometry with MATISSE will allow
significant advances in various fundamental research fields: studies
of disks around young stellar objects where planets form and evolve,
surface structures and mass loss of stars in late evolutionary stages,
and the environments of black holes in active galactic nuclei. MATISSE
is a unique instrument. As a first breakthrough it will enlarge the
spectral domain used by optical interferometry by offering the L
& M bands in addition to the N band, opening a wide wavelength
domain, ranging from 2.8 to 13 μm on angular scales of 3 mas (L/M
band) / 10 mas (N band). As a second breakthrough, it will allow
mid-infrared imaging - closure-phase aperture-synthesis imaging -
with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT)
of the VLTI. MATISSE will offer various ranges of spectral resolution
between R~30 to ~5000. In this article, we present some of the main
science objectives that have driven the instrument design. We introduce
the physical concept of MATISSE including a description of the signal
on the detectors and an evaluation of the expected performance and
discuss the project status. The operations concept will be detailed in
a more specific future article, illustrating the observing templates
operating the instrument, the data reduction and analysis, and the
image reconstruction software.
---------------------------------------------------------
Title: MASCARA: opto-mechanical design and integration
Authors: Spronck, Julien F. P.; Lesage, Anna-Léa.; Stuik, Remko;
Bettonvil, Felix; Snellen, Ignas A. G.
2014SPIE.9147E..56S Altcode:
MASCARA, the Multi-site All-Sky CAmeRA, consists of several
fully-automated stations. Its goal is to find exoplanets transiting
the brightest stars, in the mV = 4 to 8 magnitude range. Each station
contains five wide- angle cameras monitoring the near-entire sky at each
location. The five cameras are located in a temperature- controlled
enclosure and look at the sky through five windows. A housing with a
moving roof protects MASCARA from the environment. Here, we present
the opto-mechanical design of the first MASCARA station.
---------------------------------------------------------
Title: Realization and performance of cryogenic selection mechanisms
Authors: Aitink-Kroes, Gabby; Bettonvil, Felix; Kragt, Jan; Elswijk,
Eddy; Tromp, Niels
2014SPIE.9151E..0FA Altcode:
Within Infra-Red large wavelength bandwidth instruments the use of
mechanisms for selection of observation modes, filters, dispersing
elements, pinholes or slits is inevitable. The cryogenic operating
environment poses several challenges to these cryogenic mechanisms; like
differential thermal shrinkage, physical property change of materials,
limited use of lubrication, high feature density, limited space
etc. MATISSE the mid-infrared interferometric spectrograph and imager
for ESO's VLT interferometer (VLTI) at Paranal in Chile coherently
combines the light from 4 telescopes. Within the Cold Optics Bench (COB)
of MATISSE two concepts of selection mechanisms can be distinguished
based on the same design principles: linear selection mechanisms
(sliders) and rotating selection mechanisms (wheels).Both sliders and
wheels are used at a temperature of 38 Kelvin. The selection mechanisms
have to provide high accuracy and repeatability. The sliders/wheels
have integrated tracks that run on small, accurately located, spring
loaded precision bearings. Special indents are used for selection
of the slider/wheel position. For maximum accuracy/repeatability the
guiding/selection system is separated from the actuation in this case a
cryogenic actuator inside the cryostat. The paper discusses the detailed
design of the mechanisms and the final realization for the MATISSE
COB. Limited lifetime and performance tests determine accuracy, warm
and cold and the reliability/wear during life of the instrument. The
test results and further improvements to the mechanisms are discussed.
---------------------------------------------------------
Title: Manufacturing, integration, and test results of the MATISSE
cold optics bench
Authors: Bettonvil, Felix C. M.; Kroes, G.; Agoćs, T.; van Duin,
A.; Elswijk, E.; de Haan, M.; ter Horst, R.; Kragt, J.; Kuindersma,
J.; Navarro, R.; Roelfsema, R.; Schuil, M.; Tromp, T.; Venema, L.;
van Kessel, F.; Jaskó, A.
2014SPIE.9147E..7QB Altcode:
MATISSE is the second-generation mid-infrared interferometric
spectrograph and imager for ESO's Very Large Telescope Interferometer
(VLTI). NOVA-ASTRON is responsible for the Cold Optics Bench (COB),
representing the last part of the optics train where the four beams
are re-arranged, spectrally dispersed and combined. The COB consist
of two sister units, one for the LM-band, one for the N-band, which
were successively completed at NOVA-ASTRON in autumn 2013 and spring
2014. The LM-band COB is under cryogenic test in its cryostat at
MPIA/Heidelberg; the N-band COB finished cryogenic tests and has
been installed at OCA/Nice for integration together with the Warm
Optics. This paper focuses on the manufacturing, integration and test
results of the COBs, and gives an overview of the current status.
---------------------------------------------------------
Title: MASCARA: the multi-site all-sky CAameRA: concept and first
results
Authors: Lesage, A. -L.; Spronck, J. F. P.; Stuik, R.; Bettonvil,
F.; Pollaco, D.; Snellen, I. A. G.
2014SPIE.9145E..14L Altcode:
MASCARA, the Multi-site All-Sky CAmeRA, will consist of several
fully-automated stations distributed across the globe. Its goal is
to find exoplanets transiting the brightest stars, in the mV = 4 to 8
magnitude range, currently probed neither by space- nor by ground-based
surveys. The nearby transiting planet systems that MASCARA is expected
to discover will be key targets for future detailed planet atmosphere
observations. The target population for MASCARA consists mostly of hot
Jupiters. The main requirement set on MASCARA to detect these planets
around stars down to magnitude 8 is to reach a minimum Signal-to-Noise
Ratio of 100 within one hour of observation. Each MASCARA station
consists of five low-noise off-the-shelf full-frame CCD cameras, fitted
with standard Canon 24 mm , f/1.4 lenses, monitoring the near-entire sky
down to magnitude 8 at that location. Measurements have demonstrated
that the required Signal-to-Noise Ratio of 100, can be achieved in
less than thirty minutes. MASCARA aims at deploying several stations
world-wide to provide a nearly continuous coverage of the dark sky,
at sub-minute cadence. While at the faint end MASCARA is limited
mainly by photon noise, at the bright end scintillation and red noise
become the limiting factors. Instrumental noise sources are reduced
by placing the cameras in a fixed orientation and in a temperature
controlled environment. By defocusing and allowing stars to drift over
the detector, the impact of pixel-to-pixel variations on the photometry
are minimized, while taking exposures at fixed sidereal times allows
accurate cross-calibration of consecutive nights. The exposure time of
6.4 seconds gives rise to a high data acquisition rate of a MASCARA
station, around 500GB per night. In order to minimize data transport
and data storage requirements, the raw images are reduced to produce
accurate light curves in nearly real time. The first MASCARA station
will be integrated on La Palma during the summer of 2014. MASCARA test
data were taken in July 2013 with one camera targeting the transiting
exoplanet HD 189733b. Its brightness of m<SUB>V</SUB> = 7:7 is close to
the faint end of the MASCARA magnitude range. The 5 - σ detection of
the 2.8% deep transit with a 5-minute binning of the data confirms that
we will be able to detect 1% transit at the faint end within one hour.
---------------------------------------------------------
Title: Finding planets transiting the brightest stars with MASCARA
Authors: Spronck, J. F. P.; Lesage, A. -L.; Stuik, R.; Bettonvil,
F.; Snellen, I. A. G.
2014ebi..confP3.63S Altcode:
MASCARA, the Multi-site All-sky CAmeRA, is an instrument concept that
will consist of several stations distributed across the globe, with
each station containing a few low-cost wide-angle cameras to monitor the
near-entire sky at each location. Once all stations have been deployed,
MASCARA will provide a nearly 24-hour coverage of the complete dark
sky, down to magnitude 8, at sub-minute cadence. Its purpose is to
find exoplanets transiting the brightest stars (in the V=4-8 magnitude
range) - currently not probed by space- or ground-based surveys. The
nearby transiting planet systems that MASCARA will discover will be
the key targets for detailed planet atmosphere observations. Here,
we present the final design of MASCARA as well as some preliminary
results showing that the required photometric precision of 1% per hour
is achieved for the faintest stars in our magnitude range.
---------------------------------------------------------
Title: CAMS BeNeLux
Authors: Bettonvil, Felix; Johannink, Carl; Breukers, Martin
2014pim4.conf...55B Altcode:
This paper gives an overview of the current status of the BeNeLux
CAMS video meteor network as operated in the Netherlands and Belgium,
and part of the NASA funded automated meteor video surveillance
project CAMS.
---------------------------------------------------------
Title: Geminids 2012 - a spectacular show from Oman
Authors: Weiland, Thomas; Bettonvil, Felix
2014pim4.conf...89W Altcode:
The Geminids are the most reliable prominent meteor shower currently
visible. They can be observed from the whole northern hemisphere and
even low southern latitudes as well. Nevertheless, as the weather is
often unfavourable in Central Europe during December, a six-day-long
visual observing campaign was carried out from Oman in 2012. There
observing conditions were nearly perfect, especially in the Rub al-Khali
desert in the western part of the country. As a consequence, we managed
to record more than 1800 Geminids within almost 45 hours of effective
observing time. An impression of the campaign together with a summary
of the results is given.
---------------------------------------------------------
Title: High resolution photographic imaging
Authors: Bettonvil, Felix
2014pim4.conf...30B Altcode:
A high-resolution camera is described, based on DSLR technology and
long focal length lens together with a 200 cycles/sec optical shutter,
with the aim to collect higher accuracy orbital elements. The paper
describes the design considerations, test setup, and analyses and
discusses the first results.
---------------------------------------------------------
Title: CILBO - Lessons learned from a double-station meteor camera
setup in the Canary Islands
Authors: Koschny, Detlef; Mc Auliffe, Jonathan; Drolshagen, Esther;
Bettonvil, Felix; Licandro, Javier; van der Luijt, Cornelis; Ott,
Theresa; Smit, Hans; Svedhem, Hakan; Witasse, Olivier; Zender, Joe
2014pim4.conf...10K Altcode:
We have been operating a double-station meteor camera setup and have
collected more than 12 months of simultaneous observations until
mid-2014. First science is being produced. In this paper we report on
the lessons learned and provide information on what went well and what
did not. The intention is to help other teams considering setting up
similar systems to avoid the same issues.
---------------------------------------------------------
Title: The Benelux CAMS Network—status July 2013
Authors: Roggemans, Paul; Betlem, Hans; Bettonvil, Felix; Biets,
Jean-Marie; Breukers, Martin; Haas, Robert; Jobse, Klaas; Johannink,
Carl; Langbroek, Marco; Miskotte, Koen; Neels, Piet; Nijland, Jos;
ter Kuile, Casper
2014pim3.conf..173R Altcode:
A network of CAMS, "Cameras for All-sky Meteor Surveillance", is
being built up in the Benelux1 since early 2012. If weather permits,
the network has curently 18 CAMS active at 10 observing posts. More
than 2000 accurate meteor orbits were recorded so far.
---------------------------------------------------------
Title: CILBO—Two years operation of a double-station meteor camera
set-up in the Canary Islands
Authors: Koschny, Detlef; McAuliffe, Jonathan; Bettonvil, Felix;
Licandro, Javier; van der Luijt, Cornelis; Smit, Hans; Svedhem,
Høakan; Witasse, Olivier; Zender, Joe
2014pim3.conf..166K Altcode:
Since the Summer of 2011, the Meteor Research Group of the Research
and Scientific Support Department of ESA has been operating a meteor
camera on Tenerife. At the end of 2011, a second station on La Palma
was added to the set-up, completing the double-station setup CILBO
(Canary Island Long-Baseline Observatory). Here, we give an overview
of the data obtained from 1 January to 31 August 2013. The system's
availability is just below 70%.
---------------------------------------------------------
Title: EST: the largest and most sensitive spectropolarimeter
Authors: Collados, M.; Bettonvil, F.; Cavaller, L.; Ermolli, I.; Gelly,
B.; Pérez, A. : Socas-Navarro, H.; Soltau, D.; Volkmer, R.; EST Team
2013hsa7.conf..808C Altcode:
Magnetic field plays a crucial role to understand most phenomena
happening in the solar atmosphere. Sunspots, flares, prominences,
coronal mass ejections are well known examples of its interaction
with the solar plasma. To study the properties of this interaction,
one needs to analyze the imprint it leaves in the radiation through
the polarization induced in spectral lines, via the Zeeman and Hanle
effects. Outside sunspots, the polarization degree of the emitted
light is usually well below one part in one thousand, which requires
sophisticated techniques to measure it accurately. To further complicate
the situation, telescopes use mirrors and these introduce undesired
polarization which is two or three orders of magnitude larger than
that caused by the magnetic field of solar structures. For this reason,
present telescopes doing polarimetry require an adequate modelling to
correct the measured data from these spurious effects. In addition,
most of the magnetic field interactions with the plasma take place
at small scales. The best achievable angular resolution is mandatory
to adequately study magnetic phenomena. The European solar Telescope
(EST) has been defined to overcome these difficulties. Here, some
aspects of the design are described.
---------------------------------------------------------
Title: MASCARA: The Multi-site All-Sky CAmeRA
Authors: Snellen, Inas; Stuik, Remko; Otten, Gilles; Bettonvil, Felix;
Navarro, Ramon; Kenworthy, Matthew; de Mooij, Ernst; ter Horst, Rik;
Le Poole, Rudolf; Lesage, Anna-Lea; Spronck, Julien
2013EPJWC..4703008S Altcode:
The Multi-site All-Sky CAmeRA, MASCARA, is an instrument currently
in the design phase, that is aimed to find the brightest transiting
planet systems in the sky. It will consist of several stations across
the globe, each monitoring the near-entire sky using a battery of
CCD-detectors plus wide-field lenses, targeting stars in the V = 4 -
8 magnitude range. MASCARA will be able to detect individual transits
from Jupiter-size planets over this whole magnitude range, while
smaller planets will be found by co-adding transit events. We expect
to discover up to a dozen bright transit systems in this way. These
will be extremely valuable for atmospheric follow-up studies.
---------------------------------------------------------
Title: Kees Zwaan, open principle, future of high-resolution solar
telescopes
Authors: Hammerschlag, R. H.; Bettonvil, F. C. M.
2013ASPC..470..381H Altcode:
It was around the 1970s that during site-test campaigns masts were
erected up till 30 m height with sensors at several heights for the
measurement of temperature fluctuations. Kees Zwaan discovered that
the fluctuations decrease drastically at heights from about 15 m and
upward when there is some wind. The conclusion from this experience
was the open telescope principle: a telescope completely free in the
air 15 m or more above the ground. The Dutch Open Telescope (DOT)
was the pioneering demonstrator of the open-telescope technology. Now
that larger high-resolution telescopes come in view, it is time to
analyze again the principle: the essentials for proper working of the
open principle and the design consequences for the new generation of
high-resolution solar telescopes.
---------------------------------------------------------
Title: Utrecht and the European Solar Telescope
Authors: Bettonvil, F. C. M.; EST Team
2013ASPC..470..389B Altcode:
In 2008, in the quest towards large solar facilities, a pan-European
project was started to study a 4-m European Solar Telescope
(EST). As one of the major partners, Utrecht played a significant
role in the design, in particular in relation to the intended open
design, its enclosure, telescope mechanics as well its polarimetric
properties. Mid-2011 the work did result in an innovative conceptual
design for EST.
---------------------------------------------------------
Title: Digital all-sky cameras VII: Putting the camera into operation
Authors: Bettonvil, Felix
2013pimo.conf...34B Altcode:
This seventh paper about the development of a digital all-sky camera,
built around a Canon EOS 350D, Sigma 4.5mm f/2.8 EX DC fisheye lens
and liquid crystal optical chopper, describes the constructed system
and the first half year of operation.
---------------------------------------------------------
Title: The European Solar Telescope
Authors: Collados, M.; Bettonvil, F.; Cavaller, L.; Ermolli, I.; Gelly,
B.; Pérez, A.; Socas-Navarro, H.; Soltau, D.; Volkmer, R.; EST Team
2013MmSAI..84..379C Altcode:
The European Solar Telescope (EST) is a project to design, build and
operate an European Solar 4-meter class telescope to be located in the
Canary Islands, with the participation of institutions from fifteen
European countries gathered around the consortium EAST (European
Association for Solar Telescopes). The project main objective up to the
present has been the development of the conceptual design study (DS)
of a large aperture Solar Telescope. The study has demonstrated the
scientific, technical and financial feasibility of EST. The DS has been
possible thanks to the co-financing allocated specifically by the EU
and the combined efforts of all the participant institutions. Different
existing alternatives have been analysed for all telescope systems and
subsystems, and decisions have been taken on the ones that are most
compatible with the scientific goals and the technical strategies. The
present status of some subsystems is reviewed in this paper.
---------------------------------------------------------
Title: The 2011 Eta-Aquariids observing campaign from La Palma
Authors: Bettonvil, Felix; Weiland, Thomas
2013pimo.conf..115B Altcode:
Because the Eta-Aquariids, the most prominent stream for Southern
Hemisphere observers, are difficult to watch from mid-northern
latitudes, a week-long visual observing campaign was carried out
in May 2011 from La Palma, Canary Islands, Spain. There, on the
grounds of the Observatorio del Roque de Los Muchachos (ORM), at an
altitude of more than 2000 m above sea level, observing conditions
were nearly perfect. As a consequence, we managed to record more than
300 Eta-Aquariids in about 30 hours of effective observing time. An
impression of the campaign together with a summary of the results
is given.
---------------------------------------------------------
Title: Open-foldable domes with high-tension textile membranes:
The GREGOR dome
Authors: Hammerschlag, R. H.; Kommers, J. N.; Visser, S.; Bettonvil,
F. C. M.; van Schie, A. G. M.; van Leverink, S. J.; Sliepen, G.;
Jägers, A. P. L.; Schmidt, W.; Volkmer, R.
2012AN....333..830H Altcode:
Double layers of high-tensioned textile membranes were applied to the
completely open-foldable dome for the GREGOR telescope for the first
time. Simultaneous climate measurements inside and outside the dome
have proven the thermal-insulating capability of this double-layer
construction. The GREGOR dome is the result of the continuation of the
ESO research on open-foldable domes with textile structures, followed by
the research for the DOT dome with high-tensioned textile membranes. It
cleared the way to extreme stability required for astronomical practice
on high mountain sites with heavy storms and ice formation. The storm
Delta with 245 km/h 1-minute mean maximum at the location of the GREGOR
caused no problems, nor did other storms afterwards. Opening and closing
experiences up to wind speeds of 90 km/h were without problems. New
technical developments were implemented and tested at the GREGOR dome,
opening the way for application to much larger domes up to the 30 m
diameter-class range.
---------------------------------------------------------
Title: The GREGOR dome, pathfinder for the EST dome
Authors: Hammerschlag, Robert H.; Kommers, Johannes N.; Visser,
Simon; Bettonvil, Felix C. M.; van Schie, Anton G. M.; van Leverink,
Simon J.; Sliepen, Guus; Jägers, Aswin P. L.
2012SPIE.8450E..07H Altcode:
The completely open-foldable dome of the GREGOR telescope is a further
development of the DOT dome, respectively 9 and 7 meter in diameter. New
technical developments are implemented and tested at the GREGOR dome,
that are important for the design of the much larger dome for the
EST, which will be 28 meter in diameter. The GREGOR dome is the first
with more than one clamp working simultaneously for closing the dome
and bringing the membranes on the required high tension for storm
resistance. The storm Delta with 245 km/h 1-minute mean maximum
at the location of the GREGOR gave no problems nor did the storms
afterwards. Opening and closing experiences are up to wind speeds of
90 km/h without problems. Good observing circumstances never occur
with higher wind speeds. A double layer of membranes is applied in
the GREGOR construction whereas the DOT dome is equipped with a single
layer. Simultaneous climate measurements inside and outside the dome
have proven the thermal-insulation capability of this double-layer
construction. The experiences with the GREGOR showed that the elongation
by tensioning of the prestrained membrane material is much lower than
originally expected. In the meantime, more strong and stiff membrane
material is available and applied in the EST design. As a consequence,
the clamps of the EST can have a relatively much shorter length and
there is no need anymore for simultaneous operation of the clamps and
the main actuators in low speed with help of a frequency inverter. The
clamps can close after the main bow operation is finished, which
simplifies the electrical control.
---------------------------------------------------------
Title: Large-field high-resolution mosaic movies
Authors: Hammerschlag, Robert H.; Sliepen, Guus; Bettonvil, Felix
C. M.; Jägers, Aswin P. L.; Sütterlin, Peter; Martin, Sara F.
2012SPIE.8444E..06H Altcode:
Movies with fields-of-view larger than normal for high-resolution
telescopes will give a better understanding of processes on the
Sun, such as filament and active region developments and their
possible interactions. New active regions can influence, by their
emergence, their environment to the extent of possibly serving
as an igniter of the eruption of a nearby filament. A method to
create a large field-of-view is to join several fields-of-view into
a mosaic. Fields are imaged quickly one after another using fast
telescope-pointing. Such a pointing cycle has been automated at the
Dutch Open Telescope (DOT), a high-resolution solar telescope located
on the Canary Island La Palma. The observer can draw with the computer
mouse the desired total field in the guider-telescope image of the
whole Sun. The guider telescope is equipped with an H-alpha filter and
electronic enhancement of contrast in the image for good visibility of
filaments and prominences. The number and positions of the subfields
are calculated automatically and represented by an array of bright
points indicating the subfield centers inside the drawn rectangle of
the total field on the computer screen with the whole-sun image. When
the exposures start the telescope repeats automatically the sequence of
subfields. Automatic production of flats is also programmed including
defocusing and fast motion over the solar disk of the image field. For
the first time mosaic movies were programmed from stored information
on automated telescope motions from one field to the next. The mosaic
movies fill the gap between whole-sun images with limited resolution
of synoptic telescopes including space instruments and small-field
high-cadence movies of high-resolution solar telescopes.
---------------------------------------------------------
Title: Ground-based search for the brightest transiting planets with
the Multi-site All-Sky CAmeRA: MASCARA
Authors: Snellen, Ignas A. G.; Stuik, Remko; Navarro, Ramon; Bettonvil,
Felix; Kenworthy, Matthew; de Mooij, Ernst; Otten, Gilles; ter Horst,
Rik; le Poole, Rudolf
2012SPIE.8444E..0IS Altcode: 2012arXiv1208.4116S
The Multi-site All-sky CAmeRA MASCARA is an instrument concept
consisting of several stations across the globe, with each station
containing a battery of low-cost cameras to monitor the near-entire sky
at each location. Once all stations have been installed, MASCARA will
be able to provide a nearly 24-hr coverage of the complete dark sky,
down to magnitude 8, at sub-minute cadence. Its purpose is to find
the brightest transiting exoplanet systems, expected in the V=4-8
magnitude range - currently not probed by space- or ground-based
surveys. The bright/nearby transiting planet systems, which MASCARA
will discover, will be the key targets for detailed planet atmosphere
observations. We present studies on the initial design of a MASCARA
station, including the camera housing, domes, and computer equipment,
and on the photometric stability of low-cost cameras showing that a
precision of 0.3-1% per hour can be readily achieved. We plan to roll
out the first MASCARA station before the end of 2013. A 5-station
MASCARA can within two years discover up to a dozen of the brightest
transiting planet systems in the sky.
---------------------------------------------------------
Title: MATISSE: concept, specifications, and performances
Authors: Lagarde, S.; Robbe-Dubois, S.; Petrov, R. G.; Lopez, B.;
Jaffe, W. J.; Venema, L.; Berio, Ph.; Antonelli, P.; Beckmann, U.;
Bettonvil, F. C.; Graser, U.; Navarro, R.; Matter, A.
2012SPIE.8445E..2JL Altcode:
MATISSE (Multi AperTure mid-Infrared SpectroScopic Experiment) is the
future spectro-interferometer of the European Southern Observatory VLT
operating in the spectral bands L, M and N, and combining four beams
from the telescopes UTs or ATs. This paper describes the concept, the
specifications and the expected performances of the instrument. The
requirements have been established including transmission and contrast
degradation budgets. An assessment of the performances is given in
this paper taking into account the instrument and VLTI characteristics.
---------------------------------------------------------
Title: Perspective of imaging in the mid-infrared at the Very Large
Telescope Interferometer
Authors: Lopez, B.; Lagarde, S.; Antonelli, P.; Jaffe, W.; Petrov, R.;
Venema, L.; Robbe-Dubois, Sylvie; Bettonvil, F.; Berio, P.; Navarro,
R.; Graser, U.; Beckman, U.; Weigelt, G.; Vakili, F.; Henning, T.;
Gonzales, J. -C.; Wolf, S.; Bailet, C.; Behrend, J.; Bresson, Y.;
Chesneau, O.; Clausse, J. M.; Connot, C.; Dugué, M.; Fantei, Y.;
Elswijk, E.; Hanenburg, H.; Hofmann, K. H.; Heininger, M.; ter Horst,
R.; Hron, J.; Kragt, J.; Tromp, N.; Agocs, T.; Kroes, G.; Laun,
W.; Leinert, Ch.; Lehmitz, M.; Matter, A.; Menut, J. L.; Millour,
F.; Neumann, U.; Nussbaum, E.; Ottogalli, S.; Pott, J. -U.; Rigal,
F.; Roussel, A.; Schertl, D.; Vannier, M.; Wagner, K.; Mellein, M.;
Kroener, T.; Mauclert, N.; Girard, P.; Lagarde, G. M.; Mosoni, L.;
Jasko, A.; Glindemann, A.; Phan Duc, T.; Finger, G.; Ives, D.; Jakob,
G.; Percheron, I.; Avila, G.; Palsa, R.; Pozna, E.; Lizon, J. L.;
Lucuix, Ch.; Menardi, S.; Haguenauer, P.; Gitton, P.; Morel, S.;
Gonté, F.; Jolley, P.; Rupprecht, G.; Bourget, P.; Delplancke, F.;
Mehrgan, L.; Stegmeier, J.; van Belle, G.; Richichi, A.; Moorwood, A.
2012SPIE.8445E..0RL Altcode:
MATISSE is a mid-infrared spectro-interferometer combining the
beams of up to four Unit Telescopes or Auxiliary Telescopes of the
Very Large Telescope Interferometer (VLTI) of the European Southern
Observatory. MATISSE will constitute an evolution of the two-beam
interferometric instrument MIDI. New characteristics present in MATISSE
will give access to the mapping and the distribution of the material,
the gas and essentially the dust, in the circumstellar environments by
using the mid-infrared band coverage extended to L, M and N spectral
bands. The four beam combination of MATISSE provides an efficient
uv-coverage: 6 visibility points are measured in one set and 4 closure
phase relations which can provide aperture synthesis images in the
mid-infrared spectral regime. We give an overview of the instrument
including the expected performances and a view of the Science Case. We
present how the instrument would be operated. The project involves the
collaborations of several agencies and institutes: the Observatoire de
la Côte d’Azur of Nice and the INSU-CNRS in Paris, the Max Planck
Institut für Astronomie of Heidelberg; the University of Leiden and
the NOVA-ASTRON Institute of Dwingeloo, the Max Planck Institut für
Radioastronomie of Bonn, the Institut für Theoretische Physik und
Astrophysik of Kiel, the Vienna University and the Konkoly Observatory.
---------------------------------------------------------
Title: Light Curves from a Permanent Meteor Camera Station in the
Canary Islands
Authors: Koschny, D.; Bettonvil, F.; v. d. Luijt, C.; Mc Auliffe,
J.; Smit, H.; Svedhem, H.; Witasse, O.; Zender, J.
2012LPICo1667.6140K Altcode:
This presentation will present first results of a permanent meteor
double station setup in the Canary islands. In particular, it will
focus on the measured meteor light curves.
---------------------------------------------------------
Title: Data handling and control of the European Solar Telescope
Authors: Ermolli, I.; Bettonvil, F.; Cauzzi, G.; Cavaller, L.;
Collados, M.; Di Marcantonio, P.; Grivel, C.; Paletou, F.; Romano,
P.; Aboudarham, J.; Cirami, R.; Cosentino, R.; Giorgi, F.; Lafon,
M.; Laforgue, D.; Reardon, K.; Sliepen, G.
2012MSAIS..19..380E Altcode:
We describe some aspects of the facility operation that have been
considered for the design of the data handling and control of the
European Solar Telescope. The main sub-systems of the EST relevant for
the control are summarized, together with some information on current
solar data models.
---------------------------------------------------------
Title: What happened at ESA's Meteor Research Group in 2010/11?
Authors: Koschny, D. V.; McAuliffe, J.; Bettonvil, F. C. M.;
Gritsevich, M.; van der Luijt, C.; Ocaña, F.; Smit, H.; Svedhem,
H.; Zender, J. J.
2012pimo.conf...57K Altcode:
A lot of activities took place in 2010/11 in the Meteor Research Group
(MRG) of the European Space Agency's (ESA) Research and Scientific
Support Department. Both special observing campaigns as well as
continuous observations were performed, mainly with intensified video
cameras, but also still with CCD cameras. This paper gives an overview
of the activities.
---------------------------------------------------------
Title: Maximizing the Performance of Automated Low Cost All-sky
Cameras
Authors: Bettonvil, F.
2011msss.conf..363B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Polarization Optics for the European Solar Telescope
Authors: Bettonvil, F. C. M.; Collados, M.; Feller, A.; Gelly, B. F.;
Keller, C. U.; Kentischer, T. J.; López Ariste, A.; Pleier, O.;
Snik, F.; Socas-Navarro, H.
2011ASPC..437..329B Altcode:
EST, the European Solar Telescope, is a 4-m class solar telescope,
which will be located at the Canary Islands. It is currently in the
conceptual design phase as a European funded project. In order to
fulfill the stringent requirements for polarimetric sensitivity
and accuracy, the polarimetry has been included in the design
work from the very beginning. The overall philosophy has been to
use a combination of techniques, which includes a telescope with
low (and stable) instrumental polarization, optimal full Stokes
polarimeters, differential measurement schemes, fast modulation
and demodulation, and accurate calibration, and at the same time not
giving up flexibility. The current baseline optical layout consists of a
14-mirror layout, which is polarimetrically compensated and non-varying
in time. In the polarization free F2 focus ample space is reserved for
calibration and modulators and a polarimetric switch. At instrument
level the s-, and p-planes of individual components are aligned,
resulting in a system in which eigenvectors can travel undisturbed
through the system.
---------------------------------------------------------
Title: Digital All-sky cameras VI: Camera design
Authors: Bettonvil, F.
2011pimo.conf...16B Altcode:
In this sixth paper about the development of a digital All-sky camera
the final design is described. The camera is based on a Canon EOS
350D, Sigma 4.5mm/F2.8 EX DC fisheye lens and a LC-TEC liquid crystal
optical chopper.
---------------------------------------------------------
Title: Digital All-sky Cameras IV: Sinodial Shutter Design
Authors: Bettonvil, Felix
2010pim7.conf....8B Altcode: 2010pimo.conf....8B
In this fourth paper about digital all-sky cameras I describe the design
and construction of a new type of shutter for accurate determination
of the velocity of meteors. It combines sinodial modulation of the
meteor trail with frequency a nalysis for finding the velocity. Two
alternatives are discussed.
---------------------------------------------------------
Title: Perseïden vanuit Bosnië
Authors: Bettonvil, Felix
2010eRad....6..138B Altcode:
Report on visual and photographic meteor observations during the
Perseïds 2010 in Bosnia
---------------------------------------------------------
Title: The Irkutsk Barium filter for narrow-band wide-field
high-resolution solar images at the Dutch Open Telescope
Authors: Hammerschlag, Robert H.; Skomorovsky, Valery I.; Bettonvil,
Felix C. M.; Kushtal, Galina I.; Olshevsky, Vyacheslav L.; Rutten,
Robert J.; Jägers, Aswin P. L.; Sliepen, Guus; Snik, Frans
2010SPIE.7735E..85H Altcode: 2010SPIE.7735E.265H
A wide-field birefringent filter for the barium II line at 455.4nm is
developed in Irkutsk. The Barium line is excellent for Doppler-shift
measurements because of low thermal line-broadening and steep
flanks of the line profile. The filter width is 0.008nm and the
filter is tunable over 0.4nm through the whole line and far enough
in the neighboring regions. A fast tuning system with servomotor is
developed at the Dutch Open Telescope (DOT). Observations are done
in speckle mode with 10 images per second and Keller-VonDerLühe
reconstruction using synchronous images of a nearby bluecontinuum
channel at 450.5nm. Simultaneous observation of several line positions,
typically 3 or 5, are made with this combination of fast tuning and
speckle. All polarizers are birefringent prisms which largely reduced
the light loss compared to polarizing sheets. The advantage of this
filter over Fabry-Perot filters is its wide field due to a large
permitted entrance angle and no need of polishing extremely precise
surfaces. The BaII observations at the DOT occur simultaneously with
those of a fast-tunable birefringent H-alpha filter. This gives the
unique possibility of simultaneous speckle-reconstructed observations
of velocities in photosphere (BaII) and chromosphere (H-alpha).
---------------------------------------------------------
Title: European Solar Telescope: project status
Authors: Collados, M.; Bettonvil, F.; Cavaller, L.; Ermolli, I.;
Gelly, B.; Grivel-Gelly, C.; Pérez, A.; Socas-Navarro, H.; Soltau,
D.; Volkmer, R.
2010SPIE.7733E..0HC Altcode: 2010SPIE.7733E..15C
The European Solar Telescope is a project for a 4-meter class telescope
to be located in the Canary Islands. EST is promoted by the European
Association for Solar Telescopes (EAST). This is a consortium formed
by a number of research organizations from fifteen European countries
(Austria, Croatia, Czech Republic, France, Germany, Hungary, Italy,
the Netherlands, Norway, Poland, Slovak Republic, Spain, Sweden,
Switzerland, and United Kingdom). EST will specialize in high spatial
and temporal resolution using diverse instruments that can efficiently
produce two-dimensional spectropolarimetric information of the thermal,
dynamic and magnetic properties of the plasma over many scale heights
in the solar atmosphere. In this contribution, the status of the
development of the Design Study of EST is presented, emphasizing the
most important aspects of the optical design, mechanical structure, AO
and MCAO systems for wavefront correction, instruments and polarization
analysis.
---------------------------------------------------------
Title: Site-seeing measurements for the European Solar Telescope
Authors: Berkefeld, Th.; Bettonvil, F.; Collados, M.; López, R.;
Martín, Y.; Peñate, J.; Pérez, A.; Scharmer, G. B.; Sliepen, G.;
Soltau, D.; Waldmann, T. A.; van Werkhoven, T.
2010SPIE.7733E..4IB Altcode: 2010SPIE.7733E.141B
Seeing measurements are crucial for the optimum design of
(multi-conjugate) adaptive optics systems operating at solar
telescopes. For the design study of the 4-meter European Solar
Telescope, to be located in the Canary Islands, several instruments have
been constructed and operated, at the Observatorio del Roque de los
Muchachos (La Palma) and at the Observatorio del Teide (Tenerife),
to measure the properties of the ground layer and medium-high
altitude turbulence. Several units of short (42.34 cm) and two long
(323.06 cm) scintillometer bars are, or are to be, installed at
both observatories. In addition to them, two wide-field wavefront
sensors will be attached to the optical beams of the Swedish tower,
on La Palma, and of the German VTT, on Tenerife, simultaneously used
with the normal operation of the telescopes. These wavefront sensors
are of Shack-Hartmann type with ~1 arcminute field of view. In this
contribution, the instruments setup and their performance are described.
---------------------------------------------------------
Title: Mechanical design of a completely open-foldable dome for EST
Authors: Hammerschlag, Robert H.; Kommers, Johannes N. M.; van
Leverink, Simon J.; Bettonvil, Felix C. M.; Visser, Simon; Jägers,
Aswin P. L.; Sliepen, Guus
2010SPIE.7733E..0JH Altcode:
In the context of the EST design study for a 4m-class solar
telescope and a study for large open-foldable domes of the Dutch
Technology Foundation STW, a design is made for the 20 to 30m diameter
range. Detailed designs are made for three specific diameter sizes:
23, 28 and 33m. Smaller-size open-foldable domes based on tensioned
cloth and in use at the Dutch Open Telescope (7m) and the GREGOR (9m)
have proven to be all-weather stable and very effective for good seeing
conditions for solar telescopes. The cloth has shown no degradation
over the past 14 (DOT) resp. 6 (GREGOR) years of experience and no
permanent elongation with the frequent de-tensioning and tensioning
during opening and closing. The application of cloth permits a dome
design leaving, when opened, the telescope completely free without
any structure over the telescope and no massive structures besides
or under it. Basis for the new design is the available prestretched
stable cloth, which is nowadays produced in much stronger qualities than
used for DOT and GREGOR. The larger curvature radius requires larger
tension in the cloth, but combination with stronger cloth fits for the
upscaling. Calculations show that the steel construction geometries
of the GREGOR dome can be upscaled with a few adjustments. Bearings
and drives remain within normal sizes. Cost calculations show that
open-foldable domes of this size are remarkably lower in price than
closed domes. In addition, an interesting option is presented for a
semi-transparent windshield of which the position can be adapted to the
wind direction. This shield gives an effective wind protection of the
region around the primary mirror without disturbing the wind flows above
the shield and without stagnant air or big eddies behind it. It is storm
safe and the costs are only a fraction of the open-foldable dome costs.
---------------------------------------------------------
Title: The pier and building of the European Solar Telescope (EST)
Authors: Bettonvil, F. C. M.; Codina, R.; Gómez Merchán, A.;
Hammerschlag, R. H.; Hartman, J. J. M.; Hernández Suárez, E.;
Jägers, A. P. L.; Murga Llano, G.; Pelser, J. W.; Sliepen, G.
2010SPIE.7733E..34B Altcode: 2010SPIE.7733E..97B
EST (European Solar Telescope) is a 4-m class solar telescope, which
is currently in the conceptual design phase. EST will be located in
the Canary Islands and will aim at high spectral, spatial and temporal
resolution observations in the photosphere and chromosphere, using
a suite of instruments that can produce efficiently two-dimensional
spectropolarimetric information of the thermal, dynamic and magnetic
properties of the plasma over many scale heights. The pier is defined as
the construction that supports the telescope and the enclosure. It needs
a certain height to minimize daytime ground turbulence. At the bottom of
the pier a large instrument lab is located, 16 m in diameter and 10 m
high. To the pier is attached a service building that accommodates all
auxiliary services, possibly together with a separate building. Solid
concrete- and open framework piers are compared, in terms of stability,
thermal properties and flow characteristics and building structures
in terms of construction issues. FE and CFD analysis are used to give
qualitative insight in the differences between the alternatives. The
preferred alternative is a cone shaped pier surrounded by an open
framework.
---------------------------------------------------------
Title: Foldable dome climate measurements and thermal properties
Authors: Sliepen, Guus; Jägers, Aswin P. L.; Hammerschlag, Robert H.;
Bettonvil, Felix C. M.
2010SPIE.7733E..32S Altcode: 2010SPIE.7733E..95S
As part of a larger project for measuring various aspects of foldable
domes in the context of EST and with support of the Dutch Technology
Foundation STW, we have collected over a year of continuous temperature
and humidity measurements, both inside and outside the domes of the
Dutch Open Telescope (DOT) on La Palma<SUP>5</SUP> and the GREGOR
telescope on Tenerife.<SUP>6</SUP> In addition, we have measured the
wind field around each dome. Although the structure of both domes is
similar, the DOT dome has a single layer of cloth, and is situated on
top of an open tower. In contrast, the GREGOR dome has a double layer
of cloth, and is situated on top of a tower-shaped building. These
differences result in large differences in temperature and humidity
insulation when the dome is closed. We will present the changes in
temperature and humidity one can expect for each dome within one day,
and the statistics for the variations throughout a year. In addition,
we will show that the main advantage of a foldable dome is the near
instantaneous equilibration of the air inside the volume originally
enclosed by the dome and that of the environment outside the dome. This
property allows one to operate a telescope without needing expensive
air conditioning and dome skin temperature control in order to limit
dome and shell seeing effects. The measurements give also information
about the weather fluctuations at the sites of the domes. It was
observed that on small time scales the temperature fluctuations are
significantly greater during the day than during the night.
---------------------------------------------------------
Title: The heat stop for the 4-m European Solar Telescope EST
Authors: Berrilli, F.; Egidi, A.; Del Moro, D.; Manni, F.; Cocciolo,
M.; Scotto, A.; Volkmer, R.; Bettonvil, F. C. M.; Collados Vera, M.;
Cavaller Marquez, L.; Sanchez Capuchino, J.
2010SPIE.7733E..2ZB Altcode: 2010SPIE.7733E..92B
A study is presented for the realization of the heat stop for the
4-m European Solar Telescope EST, whose feasibility study will be
completed in 2011. EST is an on-axis Gregorian telescope, equipped
with a four-meter diameter primary mirror and primary focal length of
about six meters. The heat stop, positioned at the primary focus,
must be able to remove a heat load of 13 kW, while maintaining
its surfaces very close to room temperature, to avoid the onset of
seeing. In order to remove the heat, three configurations have been
taken into consideration: 1) a flat 45° inclined heat rejecter, 2)
a 45° conical heat rejecter and 3) a heat trap (made of a conical
heat rejecter and a cylindrical heat absorber). All devices include
an air removal system to avoid the formation of thermal plumes.
---------------------------------------------------------
Title: Seeing measurements with autonomous, short-baseline shadow
band rangers
Authors: Sliepen, Guus; Jägers, Aswin P. L.; Bettonvil, Felix C. M.;
Hammerschlag, Robert H.
2010SPIE.7733E..4LS Altcode: 2010SPIE.7733E.144S
There is growing interest in measuring seeing at existing and
prospective telescope sites. Several methods exist to quantify seeing,
one among them is by measuring the scintillation of solar or lunar
light using a photodiode. A shadow band ranger (SHABAR) analyses the
covariance of the signals from an array of such photodiodes, which
allows for the spatial resolution of the index of refraction above
the SHABAR device. This allows one to estimate the index of refraction
structure parameter as a function of height, C<SUP>2</SUP>n(h). Although
a SHABAR has a limited range compared to a differential image motion
monitor (DIMM) or the latest wavefront sensors, the advantage is that it
does not need telescope optics to work. A SHABAR device can be made very
compact and can operate independent of other instruments. We describe
the design of such a SHABAR device with six photodiodes that can
operate virtually indefinitely without requiring human intervention. An
inversion algorithm is used to convert the raw scintillation signals of
the photodiodes to the desired C<SUP>2</SUP>n(h) profile and a value for
the Fried parameter r0 at height zero. We show that it is possible to
perform inversions of 10 s periods in real time on relatively low-end
hardware, such as an Intel Atom based computer, which allows the results
to be presented live to astronomers, who can use this information to
help make decisions about their observation schedule.
---------------------------------------------------------
Title: The enclosure for the European Solar Telescope (EST)
Authors: Bettonvil, F. C. M.; Codina, R.; Hammerschlag, R. H.;
Jägers, A. P. L.; Kommers, J. N. M.; van Leverink, S. J.; Sliepen,
G.; Visser, S.
2010SPIE.7733E..33B Altcode: 2010SPIE.7733E..96B
The European Solar Telescope (EST) is a 4-m class solar telescope, which
is currently in the conceptual design phase. EST will be located in the
Canary Islands and aims at observations with high spectral, spatial and
temporal resolution of the solar photosphere and chromosphere. The main
purpose of the enclosure is to protect the telescope and instruments
from severe weather conditions. An enclosure is also often needed for
reducing wind buffeting on the telescope and primary mirror cell, but
on the other hand enclosures are generally considered to degrade local
seeing. In this contribution we will present the conceptual design
of the enclosure for EST. Two different concepts have been studied
in more detail: the first being a dome concept with vent gates to
enhance local flushing, the other being a retractable enclosure, with
an optional windshield. Technically both alternatives seem feasible,
but we conclude that the retractable enclosure is the less risky
solution, since it allows easier local seeing control and allows
the use of a reflecting heat stop in the primary focus. A windshield
is effective in reducing wind load on the primary mirror; although
preliminary analysis indicate that there are feasible solutions to
keep the deformation caused by wind buffeting within the requirements.
---------------------------------------------------------
Title: EST Telescope: primary mirror, support, and cooling system
Authors: Volkmer, R.; Manni, F.; Giannuzzi, M.; Scotto, A.; Cavaller,
L.; Scheiffelen, T.; Bettonvil, F.; Berrilli, F.
2010SPIE.7739E..1OV Altcode: 2010SPIE.7739E..52V
The solar telescope EST is currently in the conceptual design phase. It
is planned to be build on the Canary Islands until end of the decade. It
is specialized on polarimetric observations and will provide high
spatial and spectral observations of the different solar atmospheric
layers. The diameter of the primary mirror blank is 4.2m. Different
types of mirror shapes were investigated with respect to thermal and
mechanical characteristics. To remove the absorbed heat an air cooling
system from the back side will be applied. Additional an air flushing
system will remove remaining warm air from the front side. A major
problem of a large open telescope will be the wind load. Results of the
investigations will be shown. To achieve optimal optical performance
an active support system is planned. The primary mirror cell needs to
be stiff enough to support the primary mirror without deformation at
strong wind in case of the open telescope option, but sufficient room
for the active support system and cooling system below the backside of
the mirror is also required. Preliminary designs and analysis results
will be presented.
---------------------------------------------------------
Title: The polarization optics for the European Solar Telescope (EST)
Authors: Bettonvil, F. C. M.; Collados, M.; Feller, A.; Gelly, B. F.;
Keller, C. U.; Kentischer, T. J.; López Ariste, A.; Pleier, O.;
Snik, F.; Socas-Navarro, H.
2010SPIE.7735E..6IB Altcode: 2010SPIE.7735E.214B
EST (European Solar Telescope) is a 4-m class solar telescope, which
is currently in the conceptual design phase. EST will be located at
the Canary Islands and aims at observations with the best possible
spectral, spatial and temporal resolution and best polarimetric
performance, of the solar photosphere and chromosphere, using a
suite of instruments that can efficiently produce two-dimensional
spectropolarimetric information of the thermal, dynamic and magnetic
properties of the plasma over many scale heights, and ranging from
λ=350 until 2300 nm. In order to be able to fulfill the stringent
requirements for polarimetric sensitivity and accuracy, from the very
beginning the polarimetry has been included in the design work. The
overall philosophy has been to use a combination of techniques, which
includes a telescope with low (and stable) instrumental polarization,
optimal full Stokes polarimeters, differential measurement schemes,
fast modulation and demodulation, and accurate calibration. The
current baseline optical layout consists of a 14-mirror layout,
which is polarimetrically compensated and nonvarying in time. In the
polarization free F2 focus ample space is reserved for calibration and
modulators and a polarimetric switch. At instrument level the s-, and
p-planes of individual components are aligned, resulting in a system
in which eigenvectors can travel undisturbed through the system.
---------------------------------------------------------
Title: Data handling and control for the European Solar Telescope
Authors: Ermolli, Ilaria; Bettonvil, Felix; Cauzzi, Gianna; Cavaller,
Lluis; Collados, Manuel; Di Marcantonio, Paolo; Paletou, Frederic;
Romano, Paolo; Aboudarham, Jean; Cirami, Roberto; Cosentino, Rosario;
Giorgi, Fabrizio; Lafon, Martine; Laforgue, Didier; Reardon, Kevin;
Sliepen, Guus
2010SPIE.7740E..0GE Altcode: 2010SPIE.7740E..13E
We introduce the concepts for the control and data handling systems of
the European Solar Telescope (EST), the main functional and technical
requirements for the definition of these systems, and the outcomes
from the trade-off analysis to date. Concerning the telescope control,
EST will have performance requirements similar to those of current
medium-sized night-time telescopes. On the other hand, the science
goals of EST require the simultaneous operation of three instruments
and of a large number of detectors. This leads to a projected data
flux that will be technologically challenging and exceeds that of
most other astronomical projects. We give an overview of the reference
design of the control and data handling systems for the EST to date,
focusing on the more critical and innovative aspects resulting from
the overall design of the telescope.
---------------------------------------------------------
Title: Auxiliary full-disc telescope for the European Solar Telescope
Authors: Sobotka, Michal; Klvaña, Miroslav; Melich, Zbynék; Rail,
Zdenék; Bettonvil, Felix; Gelly, Bernard
2010SPIE.7735E..1ZS Altcode: 2010SPIE.7735E..67S
The Auxiliary Full-Disc Telescope (AFDT) will be used for the
orientation of the observer on the solar disc and in its surroundings,
for an easy guidance of the European Solar Telescope (EST) to a selected
target, and for precise coordinate measurements. AFDT can be used as an
autonomous robotic telescope for synoptic observations and records of
solar activity also when no observations are carried out at the EST main
telescope. The principal functions of AFDT and the related requirements
are summarised. The specific axial mechanical structure accommodating
the refractor optical system is outlined. The optical system and its
components are described. Two alternatives of the positional control
system - the active guiding system and the passive guiding system -
are described and their functionality is analysed.
---------------------------------------------------------
Title: European Solar Telescope: Progress status
Authors: Collados, M.; Bettonvil, F.; Cavaller, L.; Ermolli, I.; Gelly,
B.; Pérez, A.; Socas-Navarro, H.; Soltau, D.; Volkmer, R.; EST Team
2010AN....331..615C Altcode:
In this paper, the present status of the development of the design of
the European Solar Telescope is described. The telescope is devised to
have the best possible angular resolution and polarimetric performance,
maximizing the throughput of the whole system. To that aim, adaptive
optics and multi-conjugate adaptive optics are integrated in the
optical path. The system will have the possibility to correct for the
diurnal variation of the distance to the turbulence layers, by using
several deformable mirrors, conjugated at different heights. The
present optical design of the telescope distributes the optical
elements along the optical path in such a way that the instrumental
polarization induced by the telescope is minimized and independent
of the solar elevation and azimuth. This property represents a large
advantage for polarimetric measurements. The ensemble of instruments
that are planned is also presented.
---------------------------------------------------------
Title: Digital All-sky cameras V: Liquid Crystal Optical Shutters
Authors: Bettonvil, Felix
2010pim9.conf...14B Altcode: 2010pimo.conf...14B
In this fifth paper about digital All-sky cameras I present a Liquid
Crystal Optical Shutter that can be used for determination of the
velocity of meteors. The aim is to modulate the shutter signal with a
sinusoidal function and use frequency analysis to compute the velocity.
---------------------------------------------------------
Title: Open Principle for Large High-Resolution Solar Telescopes
Authors: Hammerschlag, Robert H.; Bettonvil, Felix C. M.; Jägers,
Aswin P. L.; Sliepen, Guus
2009EM&P..104...83H Altcode: 2008EM&P..tmp...38H
Vacuum solar telescopes solve the problem of image deterioration
inside the telescope due to refractive index fluctuations of the air
heated by the solar light. However, such telescopes have a practical
diameter limit somewhat over 1 m. The Dutch Open Telescope (DOT) was the
pioneering demonstrator of the open-telescope technology without need
of vacuum, now pursued in the German GREGOR. Important ingredients for
this technology are primary beam completely open to natural wind flow,
stiff but still open design by principal stiff overall geometries in
combination with carefully designed joints and completely open-foldable
dome constructions based on tensioned strong cloth. Further developments
to large sizes are made within the framework of the design study for
a European Solar Telescope (EST).
---------------------------------------------------------
Title: The meteor year of the Meteor Research Group of the European
Space Agency's Research and Scientific Support Department
Authors: Koschny, D. V.; McAuliffe, J.; Barentsen, G.; Bettonvil,
F. C. M.; Hatton, J. P.; Lowiessen, F.; Zender, J. J.
2008JIMO...36..131K Altcode:
A lot of activities took place in 2007 at the Meteor Research Group
(MRG) of the European Space Agency's (ESA) Research and Scientific
Support Department (RSSD). Both special observing campaigns as well
as continuous observations were performed, mainly with intensified
video cameras, but also with still CCD cameras. Over 1400 meteors were
observed; about 150 meteors were observed from more than one station
allowing orbit computations. In addition to collecting observational
data, ESA/RSSD further pursued the idea of setting up standards for a
`Virtual Meteor Observatory'. The activities are summarized here to
allow referencing for more detailed, scientific papers.
---------------------------------------------------------
Title: Large fully retractable telescope enclosures still closable
in strong wind
Authors: Bettonvil, Felix C. M.; Hammerschlag, Robert H.; Jägers,
Aswin P. L.; Sliepen, Guus
2008SPIE.7018E..1NB Altcode: 2008SPIE.7018E..52B
Two prototypes of fully retractable enclosures with diameters of 7 and
9 m have been built for the high-resolution solar telescopes DOT (Dutch
Open Telescope) and GREGOR, both located at the Canary Islands. These
enclosures protect the instruments for bad weather and are fully open
when the telescopes are in operation. The telescopes and enclosures
also operate in hard wind. The prototypes are based on tensioned
membrane between movable but stiff bows, which fold together to a ring
when opened. The height of the ring is small. The prototypes already
survived several storms, with often snow and ice, without any damage,
including hurricane Delta with wind speeds up to 68 m/s. The enclosures
can still be closed and opened with wind speeds of 20 m/s without any
problems or restrictions. The DOT successfully demonstrated the open,
wind-flushing concept for astronomical telescopes. It is now widely
recognized that also large future telescopes benefit from wind-flushing
and retractable enclosures. These telescopes require enclosures with
diameters of 30 m until roughly 100 m, the largest sizes for the ELTs
(Extreme Large Telescopes), which will be built in the near future. We
discuss developments and required technology for the realization of
these large sizes.
---------------------------------------------------------
Title: Contactless sub-millimeter displacement measurements
Authors: Sliepen, Guus; Jägers, Aswin P. L.; Bettonvil, Felix C. M.;
Hammerschlag, Robert H.
2008SPIE.7018E..1CS Altcode: 2008SPIE.7018E..41S
Weather effects on foldable domes, as used at the DOT and GREGOR, are
investigated, in particular the correlation between the wind field and
the stresses caused to both metal framework and tent clothing. Camera
systems measure contactless the displacement of several dome points. The
stresses follow from the measured deformation pattern. The cameras
placed near the dome floor do not disturb telescope operations. In
the set-ups of DOT and GREGOR, these cameras are up to 8 meters away
from the measured points and must be able to detect displacements of
less than 0.1 mm. The cameras have a FireWire (IEEE1394) interface
to eliminate the need for frame grabbers. Each camera captures
15 images of 640 × 480 pixels per second. All data is processed
on-site in real-time. In order to get the best estimate for the
displacement within the constraints of available processing power,
all image processing is done in Fourier-space, with all convolution
operations being pre-computed once. A sub-pixel estimate of the peak
of the correlation function is made. This enables to process the
images of four cameras using only one commodity PC with a dual-core
processor, and achieve an effective sensitivity of up to 0.01 mm. The
deformation measurements are well correlated to the simultaneous wind
measurements. The results are of high interest to upscaling the dome
design (ELTs and solar telescopes).
---------------------------------------------------------
Title: Cornelis Zwaan, open principle, and the future of
high-resolution solar telescopes
Authors: Hammerschlag, Robert H.; Bettonvil, Felix C. M.; Jägers,
Aswin P. L.; Sliepen, Guus
2008SPIE.7012E..0MH Altcode: 2008SPIE.7012E..20H
It was in the years around 1970 that during site-test campaigns for
JOSO masts were erected up till 30 m height with sensors at several
heights for the measurement of temperature fluctuations. Cornelis
(Kees) Zwaan discovered that the fluctuations decrease drastically
at heights from about 15 m and upward when there is some wind. The
conclusion from this experience was the open telescope principle: the
telescope should be completely free in the air 15 m or more above the
ground. The Dutch Open Telescope (DOT) was the pioneering demonstrator
of the open-telescope technology. Now that larger high-resolution
telescopes come in view, it is time to analyze again the principle:
(i) the essentials for proper working of the open principle; (ii)
the differences with nighttime observations particularly concerning
the seeing; (iii) the design consequences for the new generation of
high-resolution solar telescopes.
---------------------------------------------------------
Title: Fast foldable tent domes
Authors: Jägers, Aswin P. L.; Sliepen, Guus; Bettonvil, Felix C. M.;
Hammerschlag, Robert H.
2008SPIE.7018E..1RJ Altcode: 2008SPIE.7018E..56J
In the near future ELTs (Extreme Large Telescopes) will be
built. Preferably these telescopes should operate without
obstructions in the near surrounding to reach optimal seeing
conditions and avoid large turbulences with wind-gust accelerations
around large obstacles. This applies also to future large solar
telescopes. At present two foldable dome prototypes have been
built on the Canary Islands: the Dutch Open Telescope (DOT, La
Palma) and the GREGOR Telescope (Tenerife), having a diameter of
7 and 9 meter, respectively. The domes are usually fully retracted
during observations. The research consists of measurements on the two
domes. New camera systems are developed and placed inside the domes for
precise dome deformation measurements within 0.1 mm over the whole dome
size. Simultaneously, a variety of wind-speed and -direction sensors
measure the wind field around the dome. In addition, fast sensitive
air-pressure sensors placed on the supporting bows measure the wind
pressure. The aim is to predict accurately the expected forces and
deformations on up-scaled, fully retractable domes to make their
construction more economically. The dimensions of 7 and 9 meter are
large enough for realistic on-site tests in gusty wind and will give
much more information than wind tunnel experiments.
---------------------------------------------------------
Title: Determination of the Velocity of Meteors Based on Sinodial
Modulation and Frequency Analysis
Authors: Bettonvil, Felix
2008EM&P..102..205B Altcode: 2007EM&P..tmp...41B
In meteor photography the velocity of meteors is generally obtained from
a chopper which blocks periodically the incident light beam in front
of the camera lens. In this paper I examine modulation of the meteor
trail instead with a sinodial function and use frequency analysis to
compute accurately the mean atmospheric velocity.
---------------------------------------------------------
Title: Drie Palmanese winterakties op een rij: Geminiden, Ursiden
en Quadrantiden
Authors: Bettonvil, Felix
2008eRad....4...40B Altcode:
Report on visual observations of the Geminids 2007, Ursids 2007 and
Quadrantids 2008
---------------------------------------------------------
Title: IMC 2006 Proceedings now available
Authors: Bettonvil, Felix
2008JIMO...36....4B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Orioniden 2007
Authors: Bettonvil, Felix
2008eRad....4...16B Altcode:
Report on visual observations of the Orionids 2007
---------------------------------------------------------
Title: Organizer's notes
Authors: Hartman, Joost; Bettonvil, F.
2007pimo.conf....1H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Digital All-sky cameras II: A new method for velocity
determination
Authors: Bettonvil, Felix
2007pimo.conf..134B Altcode:
In this second paper about digital All-sky cameras I present a new
type of shutter for determination of the velocity of meteors which
together with frequency analysis can lead to a higher precision.
---------------------------------------------------------
Title: Digital All-sky cameras III: Effect if Peltier cooling on
fixed pattern noise
Authors: Bettonvil, Felix
2007pimo.conf..138B Altcode:
In this third paper in a series about digital All-sky cameras I describe
the problem of the camera background level which limits long exposures
and the effect of cooling to reduce it.
---------------------------------------------------------
Title: Proceedings of the International Meteor Conference, Roden 2006
Authors: Bettonvil, Felix; Kac, Javor
2007pimo.conf.....B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Een snufje Perseïden vanuit La Palma
Authors: Bettonvil, Felix
2007eRad....3..168B Altcode:
Report on visual and photographic observations of the Perseïds 2007
at La Palma, Spain
---------------------------------------------------------
Title: ESA's double station meteor program: development, deployment,
initial results.
Authors: Mc Auliffe, J.; Koschny, D.; Lowiessen, F.; Bettonvil,
F. C. M.
2007epsc.conf..730M Altcode:
Over the past 18 months ESA's meteor research group has developed,
installed and began operating 2 permanent double station meteor
observatories in the Netherlands, and on the Canary Islands. Both
systems use image intensified video cameras and baselines of
approximately 93 and 140 km, respectively, to observe the same volume
of atmosphere (near 100 km in altitude) for the luminous effects of
meteor ablation. Events captured by both cameras in either system are
analysed dynamically in order to determine atmospheric trajectories
and subsequently pre-atmospheric orbits, as well as photometrically, to
provide estimates of the initial masses of the ablating particles. Here,
the particulars of the 2 double station systems will be presented,
an overview of the analysis process will be given and the initial
results from this analysis discussed.
---------------------------------------------------------
Title: Aperture Increase Options for the Dutch Open Telescope
Authors: Hammerschlag, R. H.; Bettonvil, F. C. M.; Jägers, A. P. L.;
Rutten, R. J.
2007ASPC..368..573H Altcode: 2007astro.ph..3638H
This paper is an invitation to the international community to
participate in the usage and a substantial upgrade of the Dutch Open
Telescope on La Palma (DOT, http://dot.astro.uu.nl). <P />We first
give a brief overview of the approach, design, and current science
capabilities of the DOT. It became a successful 0.2-arcsec-resolution
solar movie producer through its combination of (i) an excellent
site, (ii) effective wind flushing through the fully open design and
construction of both the 45-cm telescope and the 15-m support tower,
(iii) special designs which produce extraordinary pointing stability of
the tower, equatorial mount, and telescope, (iv) simple and excellent
optics with minimum wavefront distortion, and (v) large-volume
speckle reconstruction including narrow-band processing. The DOT's
multi-camera multi-wavelength speckle imaging system samples the
solar photosphere and chromosphere simultaneously in various optical
continua, the G band, Ca II H (tunable throughout the blue wing),
and Hα (tunable throughout the line). The resulting DOT data sets
are all public. The DOT database (http://dotdb.phys.uu.nl/DOT)
now contains many tomographic image sequences with 0.2-0.3 arcsec
resolution and up to multi-hour duration. You are welcome to pull them
over for analysis. <P />The main part of this contribution outlines
DOT upgrade designs implementing larger aperture. The motivation
for aperture increase is the recognition that optical solar physics
needs the substantially larger telescope apertures that became useful
with the advent of adaptive optics and viable through the DOT's open
principle, both for photospheric polarimetry at high resolution and
high sensitivity and for chromospheric fine-structure diagnosis at
high cadence and full spectral sampling. <P />Our upgrade designs for
the DOT are presented in an incremental sequence of five options of
which the simplest (Option I) achieves 1.4 m aperture using the present
tower, mount, fold-away canopy, and multi-wavelength speckle imaging
and processing systems. The most advanced (Option V) offers unblocked
2.5 m aperture in an off-axis design with a large canopy, a wide 30-m
high support tower, and image transfer to a groundbased optics lab for
advanced instrumentation. All five designs employ adaptive optics. The
important advantages of fully open, wind-transparent and wind-flushed
structure, polarimetric constancy, and absence of primary-image rotation
remain. All designs are relatively cheap through re-using as much of
the existing DOT hardware as possible. <P />Realization of an upgrade
requires external partnership(s). This report about DOT upgrade options
therefore serves also as initial documentation for potential partners.
---------------------------------------------------------
Title: Leoniden 2006 vanaf La Palma
Authors: Bettonvil, Felix
2007eRad....3...10B Altcode:
Report on visual observations of the Leonids 2006 outburst as seen
from La Palma
---------------------------------------------------------
Title: Towers for Antarctic Telescopes
Authors: Hammerschlag, R. H.; Bettonvil, F. C. M.; Jägers, A. P. L.;
Nielsen, G.
2007EAS....25..265H Altcode:
To take advantage of the exceptional seeing above the boundary layer
on Antarctic sites, a high-resolution telescope must be mounted on
a support tower. An open transparent tower of framework minimizes
the upward temperature-disturbed airflow. A typical minimum height is
30m. The tower platform has to be extremely stable against wind-induced
rotational motions, which have to be less than fractions of an arc
second, unusually small from a mechanical engineering viewpoint. In
a traditional structure, structural deflections result in angular
deflections of the telescope platform, which introduce tip and tilt
motions in the telescope. However, a structure that is designed to
deflect with parallel motion relative to the horizontal plane will
undergo solely translation deflections in the telescope platform and
thus will not degrade the image. The use of a parallel motion structure
has been effectively demonstrated in the design of the 15-m tower
for the Dutch Open Telescope (DOT) on La Palma. Special framework
geometries are developed, which make it possible to construct high
towers in stories having platforms with extreme stability against
wind-induced tilt. These geometric solutions lead to constructions,
being no more massive than a normal steel framework carrying the
same load. Consequently, these lightweight towers are well suited to
difficult sites as on Antarctica. A geometry with 4 stories has been
worked out.
---------------------------------------------------------
Title: The Ba II 4554 / Hβ Imaging Polarimeter for the Dutch Open
Telescope
Authors: Snik, F.; Bettonvil, F. C. M.; Jägers, A. P. L.;
Hammerschlag, R. H.; Rutten, R. J.; Keller, C. U.
2006ASPC..358..205S Altcode:
In order to expand the high-resolution, multi-wavelength imaging
capabilities of the Dutch Open Telescope (DOT), an additional
polarimetric channel based on a 80 mÅ tunable Lyot filter for Ba
II 4554 and Hβ has been designed and constructed. The large atomic
mass and the resulting steep line wings, make Ba II 4554 particularly
suitable for the creation of photospheric Dopplergrams and Stokes-V
magnetograms. The line also yields a significant degree of linear
(scattering) polarization for observations near the limb of the Sun,
which is modified by both horizontal and vertical weak-field topologies
through the Hanle effect and hyperfine-structure level crossing. The
polarimeter is based on liquid crystal variable retarders (LCVRs)
as polarization modulators in combination with the Lyot filter's
entrance polarizer. The tunability of the LCVRs is exploited to enable
specific wavelength calibration, selection of the reference frame of
linear polarization, and optimization of instrumental polarization
cross-talk, which for the DOT is constant in time. With the future
Ba II 4554 photospheric magnetograms, we expect to be able to discern
magnetic structures of about 150 km with field strengths down to 100 G,
and that Hanle-type observations can be performed at a resolution of
about 1 arcsec. The range of applicability of Hβ imaging polarimetry
has to be explored after installation.
---------------------------------------------------------
Title: Orbit calculation of the August 15, 2002 fireball over the
Netherlands
Authors: Bettonvil, Felix
2006pimo.conf..171B Altcode:
On August 15, 2002 at 230350 UT a very bright meteor appeared above
the western part of the Netherlands. The fireball, with an estimated
magnitude of -8, and visible for about 4 seconds, was simultaneously
photographed by three Dutch all-sky cameras operated by members of Dutch
Meteor Society and the KNVWS Meteor Section, set up at Oostkapelle,
Benningbroek and Hoogmade. Measurements of the three all-sky images
and calculation of the trajectory indicated a low vanishing height
of the fireball, slightly less than 40 kilometers, and a clear
deceleration. The calculated heliocentric orbital elements show
similarities with members of the iota-Aquarid shower, and correspond
extremely well with the anti-helion ecliptical sporadic background.
---------------------------------------------------------
Title: A digital all-sky camera
Authors: Bettonvil, Felix
2006pimo.conf...90B Altcode:
We present an automated digital all-sky camera based on a Nikon Coolpix
4500 with FC-E8 fisheye lens.
---------------------------------------------------------
Title: Tunable H-alpha Lyot filter with advanced servo system and
image processing: instrument design and new scientific results with
the Dutch Open Telescope
Authors: Bettonvil, Felix C. M.; Hammerschlag, Robert H.; Sütterlin,
Peter; Rutten, Robert J.; Jägers, Aswin P. L.; Sliepen, Guus
2006SPIE.6269E..0EB Altcode: 2006SPIE.6269E..12B
The Dutch Open Telescope (DOT; http://dot.astro.uu.nl) on La Palma
is a revolutionary open solar telescope, on an excellent site, on
top of a transparent tower of steel framework, and uses natural
air flow to minimize local seeing. The DOT is a high-resolution
multi-wavelength imager capable of long-duration time series aiming
at magnetic fine structure, topology and dynamics in the photosphere
and low- and high chromosphere. In this paper we describe the latest
addition to the multi-wavelength imaging system: a Lyot H-alpha
camera channel operating at a wavelength of 656.3 nm, being of major
interest for high-chromospheric phenomena. The channel is operated
strictly synchronous with the other channels and all data are speckle
reconstructed. The channel permits profile sampling and delivers
Dopplergrams in a 15 second time cadence, up to several hours long
and adding up to a total data amount of 1.6 Terabyte/day. A dedicated
computer (DSP, DOT Speckle Processor) has been built for processing
the data overnight.
---------------------------------------------------------
Title: Towers for telescopes with extreme stability: Active or
passive?
Authors: Hammerschlag, Robert H.; Bettonvil, Felix C. M.; Jägers,
Aswin P. L.
2006SPIE.6273E..1OH Altcode: 2006SPIE.6273E..50H
High-resolution telescopes require a mechanical stability of fractions
of an arc second. Placing such a telescope on top of a tower will
improve the local seeing. An open transparent tower of framework
minimizes the upward, temperature disturbed air flow. The tower
platform has to be extremely stable against rotational motions, which
have to be less than fractions of an arc second, unusual in mechanical
engineering. Active systems can improve the stability. However, they
need sensors for position measurements, active actuators and a control
loop. The performance is limited by the available signal-to-noise
ratio. Consequently, improvement of the passive stability of large tower
structures will significantly contribute to the final stability. Special
geometries in steel framework can reach extreme passive stability of
a tower platform, particularly against rotational motions. There are
several groups of basic geometries, which lead to solutions and we
will give a systematic description. The proposed towers can be welded
or screwed together from smaller parts. This makes a construction in
adverse environments like the Antarctic region within good reach.
---------------------------------------------------------
Title: Large bearings with incorporated gears, high stiffness,
and precision for the Swedish Solar Telescope (SST) on La Palma
Authors: Hammerschlag, Robert H.; Bettonvil, Felix C. M.; Jägers,
Aswin P. L.; Scharmer, Göran B.
2006SPIE.6273E..15H Altcode: 2006SPIE.6273E..34H
The 1-meter Swedish Solar Telescope (SST) obtains images of the solar
surface with an unprecedented resolution of 0.1 arcsec. It consists
of a relatively slender tower with on top only the vacuum turret for
reflecting downward the solar beam and no protective dome. This is a
favourable situation to get good local seeing. Just in the case of some
wind, seeing is best for daytime observations, therefore the precision
bearings and drives of the elevation- and azimuth axis of the turret
have to be stiff against wind. This requires line contact between the
meshing teeth of the large gear wheel and the pinion. High preload
forces to achieve line contact are not allowed because of appearing
stick-slip effects. To reduce the risk on stick-slip a special design
of the teeth for high stiffness combined with low friction and smooth
transition from one tooth to the next was made. Furthermore, extreme
precision in the fabrication was pursued such that relatively small
contact forces give already line contact. This required a special order
of the successive fabrication steps of the combination of bearing and
gear teeth. An additional problem was the relatively thin section
of the bearings required for a compact turret construction, needed
for best local seeing and minimum wind load. Solutions for all these
problems will be discussed. For the large gears the exceptional good
DIN quality class 4 for the pitch precision and straightness plus
direction of the teeth faces was achieved.
---------------------------------------------------------
Title: Fisheye lenses
Authors: Bettonvil, F.
2005JIMO...33....9B Altcode:
In meteor astronomy the fisheye lens is well known, in particular in the
field of fireball imaging. In this paper all relevant characteristics
of the fisheye lens are described and compared with their alternatives.
---------------------------------------------------------
Title: GISOT: a giant solar telescope
Authors: Hammerschlag, Robert H.; von der Lühe, Oskar F.; Bettonvil,
Felix C.; Jägers, Aswin P.; Snik, Frans
2004SPIE.5489..491H Altcode:
A concept is presented for an extremely large high-resolution solar
telescope with an aperture of 11 m and diffraction limited for visual
wavelengths. The structure of GISOT will be transparent to wind and
placed on a transparent stiff tower. For efficient wind flushing,
all optics, including the primary mirror, will be located above
the elevation axis. The aperture will be of the order of 11 m, not
rotatively symmetrical, but of an elongated shape with dimensions
11 x 4 m. It consists of a central on-axis 4 m mirror with on both
sides 3 pieces of 2 m mirrors. The optical layout will be kept simple
to guarantee quality and minimize stray light. A Coudé room for
instruments is planned below the telescope. The telescope will not
be housed in a dome-like construction, which interferes with the open
principle. Instead the telescope will be protected by a foldable tent
construction with a diameter of the order of 30 m, which doesn"t form
any obstruction during observations, but can withstand the severe
weather circumstances on mountain sites. Because of the nature of
the solar scene, extremely high resolution in only one dimension is
sufficient to solve many exciting problems in solar physics and in
this respect the concept of GISOT is very promising.
---------------------------------------------------------
Title: DOT++: the Dutch Open Telescope with 1.4-m aperture
Authors: Bettonvil, Felix C.; Hammerschlag, Robert H.; Sütterlin,
Peter; Rutten, Robert J.; Jägers, Aswin P.; Snik, Frans
2004SPIE.5489..362B Altcode:
The Dutch Open Telescope (DOT; http://dot.astro.uu.nl) on La Palma is
a revolutionary open solar telescope, on an excellent site, on top
of a transparent steel tower, and uses natural air flow to minimize
local seeing. The aim is long-duration high-resolution imaging with
a multi-wavelength camera system. In order to achieve this, the DOT
is equipped with a diffraction limited imaging system and uses the
speckle reconstruction technique for removing the remaining atmospheric
turbulence. The DOT optical system is simple and consists currently of
a 0.45m/F4.44 parabolic mirror and a 10x enlargement lens system. We
present our plans to increase the aperture of the DOT from 0.45m to
1.4m. The mirror support and telescope top shall be redesigned, but
telescope, tower, multi-wavelength camera system and speckle system
remain intact. The new optical design permits user selectable choice
between angular resolution and field size, as well as transversal pupil
shift introducing the possibility to use obstruction free apertures up
to 65cm. The design will include a low order AO system, which improves
the speckle S/N substantially during moderate seeing conditions.
---------------------------------------------------------
Title: The Dutch Open Telescope on La Palma
Authors: Rutten, R. J.; Bettonvil, F. C. M.; Hammerschlag, R. H.;
Jägers, A. P. L.; Leenaarts, J.; Snik, F.; Sütterlin, P.; Tziotziou,
K.; de Wijn, A. G.
2004IAUS..223..597R Altcode: 2005IAUS..223..597R
The Dutch Open Telescope (DOT) on La Palma is an innovative solar
telescope combining open telescope structure and an open support tower
with a multi-wavelength imaging assembly and with synchronous speckle
cameras to generate high-resolution movies which sample different
layers of the solar atmosphere simultaneously and co-spatially at high
resolution over long durations. The DOT test and development phase is
nearly concluded. The installation of an advanced speckle processor
enables full science utilization including "Open-DOT" time allocation
to the international community. Co-pointing with spectropolarimeters
at other Canary Island telescopes and with TRACE furnishes valuable
Solar-B precursor capabilities.
---------------------------------------------------------
Title: FIFIE - Fireball Filming Equipment: All sky imaging with video
Authors: Bettonvil, F.
2004pimo.conf....8B Altcode:
This contribution revolves around the construction of a video camera
equipped with a fisheye lens for the observation of fireballs. The
described camera Fifie (Fireball Filming Equipment) will be installed
in Utrecht, centrally located in the Netherlands, being able to witness
any fireball sighting above the lowlands. It is a valuable support
for visual fireball reports as it can provide accurate timing. Such
a camera must be seen as an addition to photographic all-sky cameras
because its lower spatial resolution cannot replace them. On the other
hand, the effort to make such a camera operational is reduced to a
minimum. It has the potential to be used by a much larger group of
meteor observers, improving the quality of a fireball network too.
---------------------------------------------------------
Title: DOT tomography of the solar atmosphere. I. Telescope summary
and program definition
Authors: Rutten, R. J.; Hammerschlag, R. H.; Bettonvil, F. C. M.;
Sütterlin, P.; de Wijn, A. G.
2004A&A...413.1183R Altcode:
The Dutch Open Telescope (DOT) on La Palma is an innovative optical
solar telescope capable of reaching 0.2 arcsec angular resolution
over extended durations. The DOT presently progresses from technology
testbed to a stable science configuration providing multi-wavelength
imaging and multi-camera speckle data acquisition for tomographic
mapping of the solar atmosphere. Large-volume speckle processing will
soon enable frequent usage and community-wide time allocation, in
particular for tandem operation with other solar telescopes pursuing
spectropolarimetry and EUV imaging. We summarize the DOT hardware and
software in the context of this increasing availability and outline
the corresponding “open-DOT” program.
---------------------------------------------------------
Title: What can an urban observer do? Video work from downtown
Authors: Bettonvil, F.
2003JIMO...31...38B Altcode:
This paper demonstrates that, even from light polluted areas, useful
meteor work can be done. In the center of a medium sized city an
intensified video system was set up and the goal, instead of activity
monitoring, was to do some orbit analysis. In April 2001, around the
Lyrid maximum, multi-station observations were conducted from two
stations, and together 50~meteor trails containing five double-station
meteors were collected. As an example, three Lyrids were analyzed
and their orbits calculated. The results illustrate that it is quite
possible to do this kind of work under less favorable circumstances,
but also showed some general problems with video multi-station work:
neither radiant nor velocity could be determined accurately enough to
compute all orbital elements precisely. Possible improvements to this
are discussed.
---------------------------------------------------------
Title: Multi-wavelength imaging system for the Dutch Open Telescope
Authors: Bettonvil, Felix C.; Suetterlin, Peter; Hammerschlag, Robert
H.; Jagers, Aswin P.; Rutten, Robert J.
2003SPIE.4853..306B Altcode:
The Dutch Open Telescope (DOT) is an innovative solar telescope,
completely open, on an open steel tower, without a vacuum system. The
aim is long-duration high resolution imaging and in order to achieve
this the DOT is equipped with a diffraction limited imaging system
in combination with a data acquisition system designed for use with
the speckle masking reconstruction technique for removing atmospheric
aberrations. Currently the DOT is being equipped with a multi-wavelength
system forming a high-resolution tomographic imager of magnetic
fine structure, topology and dynamics in the photosphere and low-
and high chromosphere. Finally the system will contain 6 channels:
G-band (430.5 nm), Ca II H (K) (396.8 nm), H-α (656.3 nm), Ba II
(455.4 nm), and two continuum channels (432 and 651 nm). Two channels
are in full operation now and observations show that the DOT produces
real diffraction limited movies (with 0.2" resolution) over hours in
G-band (430.5 nm) and continuum (432 nm).
---------------------------------------------------------
Title: Large open telescope: size-upscaling from DOT to LOT
Authors: Hammerschlag, Robert H.; Jaegers, Aswin P. L.; Bettonvil,
Felix C. M.
2003SPIE.4853..294H Altcode:
The design characteristics of a large open telescope (LOT) are: (i)
an open tower with only pure translations of the platform under wind
load; (ii) an open telescope construction with extremely stiff geometry
and drives; (iii) simple optics with easy aligning and testing, but
nevertheless suitable for large auxiliary equipment like spectrographs.
---------------------------------------------------------
Title: Dutch Open Telescope: status, results, prospects
Authors: Rutten, Robert J.; Sütterlin, Peter; de Wijn, Alfred G.;
Hammerschlag, Robert H.; Bettonvil, Felix C. M.; Hoogendoorn, Piet W.;
Jägers, Aswin P. L.
2002ESASP.506..903R Altcode: 2002svco.conf..903R; 2002ESPM...10..903R
The Dutch Open Telescope (DOT) on La Palma is a revolutionary telescope
achieving high-resolution imaging of the solar surface. The DOT combines
a pioneering open design at an excellent wind-swept site with image
restoration through speckle interferometry. Its open principle is now
followed in major solar-telescope projects elsewhere. In the past three
years the DOT became the first solar telescope to regularly obtain 0.2"
resolution in extended image sequences, i.e., reaching the diffraction
limit of its 45-cm primary mirror. Our aim for 2003-2005 is to turn
the DOT into a 0.2" tomographic mapper of the solar atmosphere with
frequent partnership in international multi-telescope campaigns through
student-serviced time allocation. After 2005 we aim to triple the DOT
resolution to 0.07" by increasing the aperture to 140 cm and to renew
the speckle cameras and the speckle pipeline in order to increase
the field size and sequence duration appreciably. These upgrades will
maintain the DOT's niche as a tomographic high-resolution mapper in
the era when GREGOR, Solar-B and SDO set the stage.
---------------------------------------------------------
Title: Opening the Dutch Open Telescope
Authors: Rutten, R. J.; de Wijn, A. G.; Sütterlin, P.; Bettonvil,
F. C. M.; Hammerschlag, R. H.
2002ESASP.505..565R Altcode: 2002IAUCo.188..565R; 2002solm.conf..565R
We hope to "open the DOT" to the international solar physics
community as a facility for high-resolution tomography of the solar
atmosphere. Our aim is to do so combining peer-review time allocation
with service-mode operation in a "hands-on-telescope" education
program bringing students to La Palma to assist in the observing and
processing. The largest step needed is considerable speedup of the
DOT speckle processing.
---------------------------------------------------------
Title: Proxy Magnetometry with the Dutch Open Telescope
Authors: Rutten, R. J.; Hammerschlag, R. H.; Sütterlin, P.; Bettonvil,
F. C. M.
2001ASPC..236...25R Altcode: 2001aspt.conf...25R
No abstract at ADS
---------------------------------------------------------
Title: A Multi-Channel Speckle Imaging System for the DOT
Authors: Sütterlin, P.; Hammerschlag, R. H.; Bettonvil, F. C. M.;
Rutten, R. J.; Skomorovsky, V. I.; Domyshev, G. N.
2001ASPC..236..431S Altcode: 2001aspt.conf..431S
No abstract at ADS
---------------------------------------------------------
Title: Solar Magnetometry with the Dutch Open Telescope
Authors: Rutten, R.; Hammerschlag, R. H.; Sutterlin, P.; Bettonvil,
F. C. M.; van der Zalm, E. B. J.
2000ESASP.463..611R Altcode: 2000sctc.proc..611R
No abstract at ADS
---------------------------------------------------------
Title: The Dutch Open Telescope
Authors: Rutten, R. J.; Hammerschlag, R. H.; Bettonvil, F. C. M.
1999ASPC..158...57R Altcode: 1999ssa..conf...57R
No abstract at ADS
---------------------------------------------------------
Title: The Dutch Open Telescope at the Roque de los Muchachos
Observatory
Authors: Hammerschlag, Robert H.; Bettonvil, Felix C. M.
1998NewAR..42..485H Altcode:
We briefly describe the Dutch Open Telescope, whose innovative design
tries to get the most out of the good La Palma seeing.
---------------------------------------------------------
Title: De Dutch Open Telescope: nieuwe zonnentelescoop op La Palma.
Authors: Rutten, R.; Hammerschlag, R.; Bettonvil, F.
1997Zenit..24..481R Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Video equipment for Meteor Observations: some Modern Technology
Authors: Bettonvil, F.
1997pimo.conf...99B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Dutch Open Telescope: Status and Prospects
Authors: Rutten, R. J.; Hammerschlag, R. H.; Bettonvil, F. C. M.
1997ASPC..118..335R Altcode: 1997fasp.conf..335R
The Dutch Open Telescope represents a new solar telescope concept. Being
open rather than evacuated, it leads the way to large-aperture high
resolution telescopes. It is now being installed on La Palma.
---------------------------------------------------------
Title: The daylight fireball over the North Sea, May 29, 1994,
9<SUP>h</SUP>32<SUP>m</SUP>±1<SUP>m</SUP> UT.
Authors: Bettonvil, F.; Neijts, M.; Apeldoorn, B.
1994JIMO...22..173B Altcode: 1994WGN....22..173B
No abstract at ADS
---------------------------------------------------------
Title: De Utrechtse open toren telescoop.
Authors: Bettonvil, F. C. M.; Hammerschlag, R. H.
1993Zenit..20..327B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Wat doen de Perseïden in 1993?
Authors: Bettonvil, F.; Gloudemans, R.
1993Zenit..20..266B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Orbits of meteorite producing fireballs: The Glanerbrug -
A case study
Authors: Jenniskens, Peter; Borovicka, Jiri; Betlem, Hans; Ter Kuile,
Casper; Bettonvil, Felix; Heinlein, Dieter
1992A&A...255..373J Altcode:
At 18:32:38 UT on April 7, 1990, a breccious L-LL type chondrite fell
near Glanerbrug in the Netherlands. From visual observations of the
meteor by 200 occasional observers, a heliocentric orbit is derived by
several independent methods, including a new method using the slope
of the meteor on the sky as seen from different locations. The orbit
found has a relatively high inclination of 23 +/- 5 deg, adding weight
to the high inclination tail of meteorite producing fireballs. The
average value of i for this population matches that of the population of
near-earth asteroids, but is significantly higher than that found for
the possible meteorite producing fireballs registered in the Prairie
Network and the Meteorite Observation and Recovery Project.
---------------------------------------------------------
Title: The Glanerbrug meteorite fall.
Authors: Jenniskens, P.; Borovička, J.; Betlem, H.; Ter Kuile, C.;
Bettonvil, F.; Heinlein, D.
1992PAICz..79.....J Altcode:
The meteorite fall at Glanerbrug, at 18:32:38 UT on April 7, 1990, is
described on the basis of 200 eye witness accounts of the associated
meteor. Due to a favourable distribution of observing locations, the
atmospheric trajectory can be reconstructed from several different
approaches to the data. The orbit found has a relatively high
inclination of 23±5 degrees, adding weight to the high inclination
tail of the population distribution of meteorite dropping events.
---------------------------------------------------------
Title: De Glanerbrug, Nederlands vijfde meteoriet.
Authors: Bettonvil, F.
1990Zenit..17..425B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Perseiden 1989 vanuit Winterswijk en Heesch
Authors: Bettonvil, Felix
1989Rad....11..112B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Vuurbollen in april.
Authors: Bettonvil, F.
1987Zenit..14..406B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Orioniden 1987 te Vught
Authors: Bettonvil, Felix
1987Rad.....9..100B Altcode:
No abstract at ADS
