Author name code: kovacs
ADS astronomy entries on 2022-09-14
author:"Kovacs, Agnes" year:1960-1999 -aff:"Cambridge" -aff:"Pasadena"
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Title: Design of the Gemini near-infrared spectrometer
Authors: Elias, Jonathan H.; Vukobratovich, Daniel; Andrew, John R.;
Cho, Myung K.; Cuberly, Randy W.; Don, Ken; Gerzoff, Allen; Harmer,
Charles F.; Harris, D.; Heynssens, Julie B.; Hicks, J.; Kovacs,
A.; Li, Cheng; Liang, M.; Moon, Il K.; Pearson, Earl T.; Plum, G.;
Roddier, Nicolas A.; Tvedt, J.; Wolff, Richard J.; Wong, Woon-Yin
Bibcode: 1998SPIE.3354..555E
Altcode:
The design of a near-IR spectrometer for the Gemini 8m telescopes
is described. This instrument, GNIRS, provides coverage from 0.9
to 5.5 micrometers at several spectral resolutions and two pixel
scales. Capabilities include an imaging mode intended primarily for
acquisition, a cross- dispersed mode covering wavelengths from 0.9
to 2.5 micrometers , and provisions for an integral field unit. The
design of the GNIRS is conservative, as it must meet tight schedule
and resource constraints; it nonetheless provides high throughput and
operational efficiency, minimal flexure, and the flexibility needed to
support queue observing. The optics are a combination of diamond-turned
metal optics for the fore-optics and collimator, and refractive optics
for the cameras. The mechanism include a two-axis grating turret; all
mechanism are deposited by means of internal detents. The instrument
achieves low flexure within its weight budget by the use of a modular
structure composed of cylindrical light-weighted sections into which
individual mechanisms and optics modules are mounted. Extensive analyses
of mechanical and optical performance have been performed. The GNIRS
has passed its critical design review, and fabrication is now underway.
Title: Sunspot motion and flare occurrences
Authors: Dezsö, L.; Kovács, Á.
Bibcode: 1998PAICz..88...17D
Altcode:
No abstract at ADS
Title: Formation of a Solar Filament Channel
Authors: Gaizauskas, V.; Zirker, J. B.; Sweetland, C.; Kovacs, A.
Bibcode: 1997ApJ...479..448G
Altcode:
We present observations of the early stages of formation of a filament
channel when a compact activity complex emerged in a previously quiet,
near-equatorial area. In a few hours, and while flux was rising rapidly
in one bipolar component in the complex, H alpha fine structure
overlying a polarity inversion zone organized into a conspicuous
pattern of parallel fibrils enclosing the trailing end of the new
activity complex. Yet it took another 4 days for a stable filament
to form inside that pattern. It did so at a place where migrating
positive polarity flux from the new activity complex contacted the
negative polarity flux in a plage of an adjacent decaying bipolar
active region. In contrast, no filament formed along an existing
channel inside the adjacent decaying region; the opposite-polarity
fluxes on the borders of the existing channel showed no signs of
convergence. We attribute the fibril-aligning forces in the new channel
to the horizontal component of an extended nonpotential magnetic field
caused by currents in the multipolar activity complex. The channel is,
in this view, an elementary part of the magnetic topology of an activity
complex. We propose that the later formation of the filament in the
new channel requires an additional and separate process. A plausible
candidate for this second step is the development of a current sheet
at the site of converging magnetic flux.
Title: Detection and Characterization of the Cumulene Carbenes H2C5
and H2C6.
Authors: McCarthy, M. C.; Travers, M. J.; Kovacs, A.; Chen, W.;
Novick, S. E.; Gottlieb, C. A.; Thaddeus, P.
Bibcode: 1997Sci...275..518M
Altcode:
No abstract at ADS
Title: Sunspot Motion and Flare Occurrences
Authors: Dezső, L.; Kovács, Á.
Bibcode: 1997eaun.book....3D
Altcode:
No abstract at ADS
Title: Laboratory detection of the C_8_H radical.
Authors: McCarthy, M. C.; Travers, M. J.; Kovacs, A.; Gottlieb, C. A.;
Thaddeus, P.
Bibcode: 1996A&A...309L..31M
Altcode:
The C_8_H radical has been detected in an argon-acetylene discharge,
conclusively confirming the identification by Cernicharo and Guelin in
the accompanying Letter of their new linear molecule in IRC+10216. In
addition to the ground ^2PI_3/2_ rotational ladder, the
^2PI_1/2_ ladder 19cm^-1^ above ground has been detected, and
the entire fine structure-rotational spectrum calculated. The standard
^2PI Hamiltonian fits the laboratory measurements of more
than 30 radio lines between 80 and 100GHz to high accuracy; yields
precise values for the rotational, fine structure, and lambda-doubling
constants; and allows the astronomically most interesting lines in the
radio spectrum to be predicted to an uncertainty of 0.1km/s or better.
Title: On the Differential Rotation of the Solar Photosphere
Authors: Dezso, L.; Kovacs, Agnes
Bibcode: 1994SoPh..151..385D
Altcode:
It is shown that sunspots as tracers can give the same results for the
differential rotation of the solar photosphere as the Doppler-shift
measurements, if the sunspots used have only insignificant motion
relative to their immediate photospheric surroundings.
Title: On the differential rotation of the solar photosphere.
Authors: Dezsö, L.; Kovács, A.
Bibcode: 1994soro.conf..136D
Altcode:
No abstract at ADS
Title: An account of sunspot group developments on the basis of the
`Debrecen Photoheliographic Results'
Authors: Dezsö, L.; Kovács, Á.
Bibcode: 1994smf..conf...55D
Altcode:
No abstract at ADS
Title: An Analysis of Surges Triggered by a Small Flare
Authors: Kovacs, Agnes; Dezso, L.
Bibcode: 1990SoPh..129..313K
Altcode:
On 22 October, 1980, near the solar central meridian in the western
vicinity of a large spot group, a subflare of the two-ribbon type was
observed. Three surges were associated with this flare. Their starting
points were situated close to the principal flare patches on both sides
of a short filament that was visible for only a few hours. True flow
velocities and decelerations along the arch-shaped surge trajectories
have been determined for two of the surges. The highest velocities
were found at the onset of the surges.
Title: Problem of short-term prediction of solar flare activity. V -
Spatial consistence between hard X-ray enhancement and strong X-ray
appearance
Authors: Jakimiec, M.; Kovacs, A.
Bibcode: 1990AcA....40..305J
Altcode:
The aim of this paper is verification of the suggestion that small faint
flares with enhanced harder X-ray flux may be precursors of strong flare
activity and, as precursors, they should be located in the sunspot
group where strong X-ray flares occur. Statistical analysis is based
on the observations obtained at Debrecen Heliophysical Observatory
and also on the standard flare observations given in Solar Geophysical
Data. The analysis proved that the hypothesis of random location over
the area of the sunspot group of both precursors and the other faint
flares should be rejected. Consequently, it may be said that, before
strong flares, the precursors appear more often in their vicinity than
the other faint flares do.
Title: An Analysis of Surges Triggered by a Small Flare
Authors: Kovács, Agnes; Dezsõ, L.
Bibcode: 1990LNP...363..261K
Altcode: 1990IAUCo.117..261K; 1990doqp.coll..261K
On 22 October 1980, near the solar central meridian, in the western
vicinity of the large spot group, a subflare of the two-ribbon type
was observed. Three surges were associated with this flare. Their
starting points were situated close to the principal flare patches
on both sides of a short filament that was visible for only a few
hours. True flow velocities and decelerations along the arch-shaped
surge trajectories have been determined for two of the surges. The
event was studied from a series of Ha on- and off-band filter-grams
taken through the Debrecen coronagraph of 53 cm aperture.
Title: Photoheliographic results for the year 1977.
Authors: Dezsö, L.; Gerlei, O.; Kovács, Á.
Bibcode: 1987PDHO....1...11D
Altcode:
The paper contains the results of measurements of positions and areas
of sunspots observed during the year 1977.
Title: Development of sunspot groups related to the solar differential
rotation during the early period of a new solar cycle.
Authors: Dezso, L.; Kovacs, A.
Bibcode: 1987PAICz..66...81D
Altcode: 1987eram....1...81D
Diverse spot distributions and the principal spot motions within the
groups, as well as the local solar rotation in several regions of spot
groups by means of tracers of spot positions have been determined. The
most important characteristics found are presented.
Title: A comparison between Greenwich and Debrecen measurements of
sunspot positions.
Authors: Kovács, Á.
Bibcode: 1987PDHO....1..211K
Altcode:
No abstract at ADS
Title: Sunspot motion as precedents of increasing flare activity
Authors: Kovacs, Agnes; Dezso, L.
Bibcode: 1986AdSpR...6f..29K
Altcode: 1986AdSpR...6...29K
Sunspot motion determined on the basis of white-light heliograms taken
in Debrecen and Gyula, during FBS Actions and on other occasions,
were compared with flare occurrence data. Several examples were found
showing convincingly that magnetic shears caused by the relative motion
of originally unconnected sunspot pairs of opposite polarity are often
followed by some prominent flares and/or a substantial increase in
flare activity for a period of one day or so.
Title: An analysis of the relationship between X-ray and H-alpha
flares
Authors: Jakimiec, M.; Kovács, Á.
Bibcode: 1986CoSka..15..671J
Altcode:
No abstract at ADS
Title: Sunspot motion in Hale region No. 18430
Authors: Kovács, Á.; Dezsö, L.
Bibcode: 1986CoSka..15..103K
Altcode:
On the basis of sunspot positions, measured on full-disc white-light
heliograms, the spot motions of a new solar active region have
been studied. All spots were followed from birth over their whole
discpassage in the period of June 16 - 26, 1982. Within a few days
a large sunspot group was fully developed that was associated with
a number of major flare occurrences (two of them have been reported
even as white-light flares).
Title: On the quasi-homologous limb flares observed on 3 August 1981
Authors: Dezsö, L.; Fludra, A.; Gerlei, O.; Jakimiec, J.; Kovács,
Á.; Pettauer, T.
Bibcode: 1986AdSpR...6f..65D
Altcode: 1986AdSpR...6...65D
Five limb flares and a large surge, triggered obviously by the second
flare, have been investigated on the basis of Hα on- and off-band
heliograms and X-ray data obtained during a 6-hour period on 3 August
1981. In addition, in the vicinity of the flare location the sunspots
and filaments were followed by observations over several of the former
days too. Emphasis was layed on the ascending motion in the course of
flare build-up and on the time evolution of the flare energy release
using GOES observations in the case of the first and second flares. It
was found that their ascending Hα flare kernels, which reached to a
height of 20-25×103 km, have been the main center both
the source and the starting points of flare loops and perhaps also
the main site of the soft X-ray emissions.
Title: Sunspot motions and magnetic shears as precusors of flares
Authors: Dezso, L.; Csepura, G.; Gerlei, O.; Kovacs, A.; Nagy, I.
Bibcode: 1984AdSpR...4g..57D
Altcode: 1984AdSpR...4...57D
Using full-disc white light photoheliograms, we have studied umbrae
motion and variations in sunspot areas in a large activity complex
over 4 solar rotations. On the basis of the observational data we
illustrate with typical examples to what extent rapid spot motions
are associated with flare occurrences.
Title: A note on flare loops.
Authors: Dezsö, L.; Kovács, Á.
Bibcode: 1983PDHO....5..317D
Altcode: 1984PDHO....5..317D
It is shown that even the flash phase of a typical flare consists mainly
of loops, when the bulk of energy release took place. Consequently
the flare phenomenon may be regarded as a loop system temporarily in
a highly excited state.
Title: A Note on Sunspot Group Development SPOT Motions and Solar
Rotation
Authors: Dezso, L.; Kovacs, A.
Bibcode: 1981PDHO....4...35D
Altcode:
No abstract at ADS
Title: Motions in the solar atmosphere associated with the white
light flare of 11 July 1978
Authors: Dezso, L.; Gesztelyi, L.; Kondas, L.; Kovacs, A.; Rostas, S.
Bibcode: 1980SoPh...67..317D
Altcode:
Series of white light heliograms and oft- and on-band Hα filtergrams
have been obtained, with an average spatial resolution of 1″, to study
the flare active McMath region 15403 on 11 July, 1978. A great number
of accurate heliographic positions were determined for the umbrae, the
white light flare patches and several bright Hα flare knots, as well
as along the principal zero filament and an arch prominence. Using the
measured heliographic coordinates of these objects their motions could
be analyzed in some detail. The velocities of several different objects
could be deduced from the coordinates. Since the heliocentric angle
of the region was about 45°, the variation in apparent heliographic
coordinates also enabled some variations in heights to be determined.
Title: The development of the sunspot group associated with the
white light flare of July 1974.
Authors: Kovács, Á.
Bibcode: 1977PDHO....3..207K
Altcode:
No abstract at ADS
Title: Results of a study of the active region McMath 13736 according
to the cooperative KAPG program "The birth of active regions".
Authors: Alikaeva, K. V.; Akhmedov, Sh. B.; Baranovskij, Eh. A.;
Gel'Frejkh, G. B.; Dezsoe, L.; Gyertyanos, G.; Ioshpa, B. A.; Ishkov,
V. N.; Kalman, B.; Kartashova, L. G.; Koval'Chuk, M. M.; Kovacs,
A.; Laba, I. S.; Olijnyk, P. A.; Orudzhev, Eh. Sh.; Mamedov, S. G.;
Rakhubovskij, A. S.; Seidov, A. G.; Sikora, J.; Stepanyan, N. N.
Bibcode: 1976veao.conf...21A
Altcode:
No abstract at ADS
Title: Proper motions of sunspot groups Nos. 50 and 52 of S.D., 1975.
Authors: Dezsoe, L.; Gyertyanos, G.; Kalman, B.; Kovacs, A.
Bibcode: 1976veao.conf...48D
Altcode:
No abstract at ADS
Title: Investigations on the program "Rapid variations of solar
magnetic fields", IV. Motions of sunspot umbrae.
Authors: Dezsoë, L.; Gyertyáos, G.; Kálmán, B.; Kovács, A.
Bibcode: 1971BSolD1971...77D
Altcode:
No abstract at ADS
Title: The Migration of Sunspot Activity Along Solar Meridians
and Parallels
Authors: Dezsö, L.; Gerlei, O.; Kovács, Ágnes
Bibcode: 1968IAUS...35...70D
Altcode:
No abstract at ADS
Title: Das Flächenverhältnis von Penumbra zur Umbra in
Sonnefleckengruppen
Authors: Dezsö, L.; Kovács, A.
Bibcode: 1965BAICz..16...76D
Altcode:
No abstract at ADS