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Author name code: bagare
ADS astronomy entries on 2022-09-14
author:"Bagare, Somashekar Pundalikarao"
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Title: An attempt of identification of barium hydride molecular
lines in sunspot umbral spectra
Authors: Karthikeyan, B.; Shanmugapriya, G.; Rajamanickam, N.; Bagare,
S. P.
2020NewA...7801366K Altcode:
A high-resolution sunspot umbra spectrum recorded in National Solar
Observatory, Kitt Peak in the visible and infrared wave number
range 13, 600 - 25, 000cm<SUP>-1</SUP> was taken in the present
study for identifying the rotational lines of barium hydride (BaH)
molecule. Number of chance coincidences was evaluated for the A
<SUP>2</SUP>Π<SUB>1/2</SUB> - X <SUP>2</SUP>Σ ((0,0), (1,1), (2,2),
(1,0), (2,1)), A <SUP>2</SUP>Π<SUB>3/2</SUB> - X <SUP>2</SUP>Σ ((0,0),
(1,1), (2,2)), B <SUP>2</SUP>Π<SUB>1/2</SUB> - X <SUP>2</SUP>Σ
(0,0), B <SUP>2</SUP>Π<SUB>3/2</SUB> - X <SUP>2</SUP>Σ (0,0),
C <SUP>2</SUP>Σ - X <SUP>2</SUP>Σ ((1,1), (1,0), (2,2), (2,1),
(3,2)) and D <SUP>2</SUP>Σ - X <SUP>2</SUP>Σ ((1,0), (2,0),
(3,0), (4,0), (5,0), (8,0), (9,0)) band systems of BaH using
line identification procedure. The obtained number of chance of
coincidences was compared with I- parameter values. The highly
resolved rotational lines were chosen to evaluate equivalent widths
using triangle approximation method. The effective rotational
temperatures were calculated for the bands (0,0), (1,1), (2,2)
and (2,1) of A <SUP>2</SUP>Π<SUB>1/2</SUB> - X <SUP>2</SUP>Σ,
(0,0) (1,1) and (2,2) of A <SUP>2</SUP>Π<SUB>3/2</SUB> - X
<SUP>2</SUP>Σ, B <SUP>2</SUP>Π<SUB>1/2</SUB> - X <SUP>2</SUP>Σ
(0,0) and B <SUP>2</SUP>Π<SUB>3/2</SUB> - X <SUP>2</SUP>Σ (0,0)
of BaH molecule. The rotational temperature values calculated for
these bands were found to be in the range 1185 - 3514 K. They were
also compared with the already reported sunspot temperatures.
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Title: Examining Barium Deuteride Molecules in Sunspots
Authors: Karthikeyan, B.; Shanmugapriya, G.; Rajamanickam, N.; Bagare,
S. P.
2018RNAAS...2...21K Altcode: 2018RNAAS...2a..21K
No abstract at ADS
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Title: Abnormal rotation rates of sunspots and durations of associated
flares
Authors: Suryanarayana, G. S.; Hiremath, K. M.; Bagare, S. P.;
Hegde, M.
2015A&A...580A..25S Altcode:
Context. Short-duration and long-duration flares are important in terms
of their association with coronal heating and coronal mass ejections,
respectively. Sunspot motions in the photosphere have been known to be
associated with flare occurrences. <BR /> Aims: We study the association
between the abnormal rotation rates (longitudinal displacement in a
given latitude in contrast with the rotation of spots around their
umbral centre) of sunspots and flare duration. <BR /> Methods: We
compute the rotation rates of sunspots for different days during their
evolution. We consider rotation rates that are in excess of one standard
deviation as abnormal rotation rates. Also, the duration of time
between the initial and final stages of the flares are computed. <BR
/> Results: Using Kodaikanal Observatory white light picture and
GOES soft X-ray flare data, we find that a good association with a
high significance exists between abnormal rotation rates of sunspots
and flare durations. In contrast, we find that duration of flare is
independent of sunspot area. <BR /> Conclusions: The present study
suggests that sub-surface dynamics plays a dominant role in determining
the duration and rate of dissipation of energy during flares.
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Title: A Detailed Analysis of Barium Oxide Molecular Lines in Sunspot
Umbral Spectra
Authors: Shanmugapriya, G.; Karthikeyan, B.; Balachandrakumar, K.;
Rajamanickam, N.; Bagare, S. P.
2015SoPh..290.1569S Altcode: 2015SoPh..tmp...58S
It is essential to know the composition of atoms or molecules present
in the astrophysical objects concerned to determine the physical
and chemical nature of a solar or stellar region. With the aim to
identify them clearly, we therefore analyzed the rotational lines of
eleven bands of the A<SUP>1</SUP>Σ-X<SUP>1</SUP>Σ<SUP>+</SUP> system
and three bands of the A<SUP>'1</SUP>Π-X<SUP>1</SUP>Σ<SUP>+</SUP>
system of the barium oxide (BaO) molecule in high-resolution sunspot
umbra spectra provided by the National Solar Observatory, Kitt
Peak, in the visible and infrared wavenumber range 13 600 - 25 000
cm<SUP>−1</SUP>. We confirm rotational lines in several bands of the
BaO molecule by following the line identification technique, in which
the positive result of chance coincidences is observed. We additionally
confirmed the BaO molecule in sunspots by evaluating the rotational
temperature. The equivalent widths for the well-resolved lines have been
observed in the spectra, and accordingly, the rotational temperature of
the band systems were determined by plotting the graph between J(J+1)
and log(W/J). The estimated effective rotational temperature values for
the bands of A-X and A'-X vary from 1000 to 3500 K, which agrees well
with the reported temperatures obtained by identifying other diatomic
molecules in sunspot umbrae. The present work therefore provides clear
evidence of the existence of the BaO molecule in sunspot umbral regions.
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Title: Evaluation of the Effective Temperature of Sunspots Using
Molecular Parameters of AlF
Authors: Balachandrakumar, K.; Raja, V.; Karthikeyan, B.; Bagare,
S. P.; Rajamanickam, N.
2015AdAst2015E...1B Altcode:
No abstract at ADS
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Title: Temporal asymmetry in aerosol optical characteristics: A case
study at a high-altitude station, Hanle, in Ladakh region
Authors: Ningombam, Shantikumar S.; Bagare, S. P.; Srivastava, A. K.;
Kanawade, V. P.; Singh, Rajendra B.; Padhy, Sangita K.
2014JASTP.121..123N Altcode:
Diurnal features of aerosol optical depth (AOD) at a high-altitude
station, Hanle (4500 m amsl) in the western Himalayas, were studied
using direct/diffuse solar irradiance measurement from a Skyradiometer
(Prede) during October 2007 to December 2010. The study reveals
a diurnal asymmetry in the measured aerosol characteristics, with
three types of diurnal variation in AOD. Among them, Types I and II
are prominent during pre-monsoon, while Type III dominates during
post-monsoon. Type I appears to be associated with new-particle
formation process from gaseous precursors, in addition to the
combination of anthropogenic and desert-dust aerosols, probably
brought by the prevailing westerly/south-westerly winds during
the pre-monsoon season. The diurnal feature of the Type II may be
attributed by the transported desert-dust aerosols brought by the
prevailing winds. Further, Type III may be associated with the aged
background aerosols over the region, pertaining to a small contribution
from gaseous precursors.
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Title: Solar Astronomy at High Altitude
Authors: Hasan, S. S.; Bagare, S. P.; Rangarajan, K. E.
2014PINSA..80..815H Altcode:
No abstract at ADS
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Title: Dynamic responses of sunspots to their ambient magnetic
configuration
Authors: Bagare, S. P.
2011IAUS..273..308B Altcode:
In our earlier study of a revisit of the classic Wilson Effect,
it was found that a large proportion of sunspots do not display the
geometric effect which is ascribed to a depression of the umbra. It
was shown that the presence or absence of the effect, observed close
to the limb, depends upon the ambient magnetic configuration of the
sunspot. In this follow up study, we look for the impact of changes
in ambient magnetic configuration on the measurable properties of
sunspots during their disk passage, using observations obtained at the
Kodaikanal observatory during 1978-80. Digitized photoheliogram data
were used to examine and measure areas of spots and their umbrae for
101 cases. Magnetic field measures published by the Academy of sciences,
Leningrad were used to evaluate the ambient magnetic configuration. The
results indicate that the extent of magnetic bipolarity is associated
with changes in the proportion of the area of the penumbra to that
of the umbra. In regular spots, the relative area of penumbra reduces
with reduction in the strength of ambient opposite polarity spots and
pores. However, in the presence of pore sized blob(s) in penumbra,
and with associated emerging fluxes, the penumbra is significantly
enlarged. But in the presence of a light bridge or a split umbra,
the relative area of penumbra is considerably reduced.
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Title: On the Rotational Temperature of AlH in Sunspots
Authors: Karthikeyan, B.; Rajamanickam, N.; Bagare, S. P.
2010SoPh..264..279K Altcode: 2010SoPh..tmp..113K; 2010SoPh..tmp..125K
A search has been carried out for the presence of rotational
lines of two bands of the (0, 0) and (1, 1) A <SUP>1</SUP>Π - X
<SUP>1</SUP>Σ<SUP>+</SUP> system of the AlH molecule in the high
resolution Fourier Transform Spectra of sunspots observed at the
National Solar Observatory at Kitt Peak. Though the presence of the AlH
molecule in sunspots was confirmed by Wallace, Hinkle, and Livingston
(An Atlas of Sunspot Umbral Spectra in the Visible from 15 000 to 25 000
cm<SUP>−1</SUP> (3920 to 6664 Å), Tech. Rep. 00-001, National Solar
Observatory, Tucson, AZ, 2000), there is no report on the rotational
temperature in the literature by identifying AlH molecular lines. The
results obtained in this new search using a suitable identification
technique are compared with the results reported by Wallace, Hinkle, and
Livingston (2000). In view of the fact that the rotational temperatures
of the molecules could be used to test photospheric and sunspot models,
the effective rotational temperature for the (0, 0) band of the A -
X system of AlH molecule is estimated by measuring the equivalent
widths of well resolved spectral lines and its value justifies the
existence of the AlH molecule in sunspots.
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Title: Solar Physics at the Kodaikanal Observatory: A Historical
Perspective
Authors: Hasan, S. S.; Mallik, D. C. V.; Bagare, S. P.; Rajaguru, S. P.
2010ASSP...19...12H Altcode: 2009arXiv0906.0144H; 2010mcia.conf...12H
The Kodaikanal Observatory traces its origins to the East India Company,
which started an observatory in Madras "for promoting the knowledge of
astronomy, geography, and navigation in India." Observations began in
1787 at the initiative of William Petrie, an officer of the Company,
with the use of two 3-in achromatic telescopes, two astronomical
clocks with compound pendulums, and a transit instrument. By the early
nineteenth century, the Madras Observatory had already established a
reputation as a leading astronomical center devoted to work on the
fundamental positions of stars, and a principal source of stellar
positions for most of the southern hemisphere stars. John Goldingham
(1796-1805, 1812-1830), T.G. Taylor (1830-1848),W.S. Jacob (1849-1858),
and Norman R. Pogson (1861-1891) were successive Government Astronomers
who led the activities in Madras. Scientific highlights of the work
included a catalogue of 11,000 southern stars produced by theMadras
Observatory in 1844 under Taylor's direction using the new 5-ft
transit instrument.
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Title: Aerosol optical properties retrieved using Skyradiometer at
Hanle in western Himalayas
Authors: Verma, Neeharika; Bagare, S. P.; Ningombam, Shantikumar Singh;
Singh, Rajendra B.
2010JASTP..72..115V Altcode:
A Skyradiometer was installed at Hanle in Ladakh, in October 2007 as
a part of the site characterization program for the proposed National
Large Solar Telescope project. Aerosol optical depth (AOD), single
scattering albedo (SSA), volume size distribution, and refractive
indices were retrieved at five spectral channels, using measurements
of direct and diffuse solar irradiation. At 500 nm, the yearly average
values of AOD and SSA were found to be 0.05 and 0.965, respectively. The
volume size distribution shows a general bimodal behavior with two
peaks at around 7-10 and with an occasional tri-modal behavior.
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Title: Revisit of the Classic Wilson Effect
Authors: Bagare, S. P.
2010ASSP...19..398B Altcode: 2010mcia.conf..398B
We have examined theWilson effect in 580 epochs of sunspots observed at
the Kodaikanal Observatory. Only unipolar spots that are well isolated
from opposite polarity spots or pores (49%) exhibit the classic Wilson
effect. The larger the isolation, the stronger is the effect. Unipolar
spots also show a decrement of the effect that seems to be related to
age. However, bipolar spots (45%) do not display theWilson effect,
while spots associated with a mixed-polarity magnetic configuration
(6%) show an inverse effect. We are now studying dynamic responses of
spot penumbrae to their ambient magnetic configuration.
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Title: On the Effective Temperature of Sunspot Umbrae using Beryllium
Hydride Isotopomer Lines
Authors: Sangeetha, R.; Sriramachandran, P.; Bagare, S. P.;
Rajamanickam, N.; Shanmugavel, R.
2009SerAJ.179...95S Altcode:
A search for fourteen bands of the visible and infrared systems of the
beryllium hydride isotopomers, in addition to the previously identified
bands A - X(0, 0; 1, 1; 2, 2) for BeH, A - X(0, 0; 1, 1; 2, 2) for
BeD and A - X(0, 0; 1, 1; 2, 2) for BeT molecules was conducted. The
equivalent widths were measured for the well isolated identified lines
of the strongest band and the effective temperatures were estimated
for the systems for which the presence of hints is confirmed.
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Title: Intensity Oscillation in the Corona as Observed during the
Total Solar Eclipse of 29 March 2006
Authors: Singh, Jagdev; Hasan, S. S.; Gupta, G. R.; Banerjee, D.;
Muneer, S.; Raju, K. P.; Bagare, S. P.; Srinivasan, R.
2009SoPh..260..125S Altcode:
We obtained the images of the eastern part of the solar corona in the
Fe XIV 530.3 nm (green) and Fe X 637.4 nm (red) coronal emission lines
during the total solar eclipse of 29 March 2006 at Manavgat, Antalya,
Turkey. The images were obtained using a 35 cm Meade telescope equipped
with a Peltier-cooled 2k × 2k CCD and 0.3 nm pass-band interference
filters at the rates of 2.95 s (exposure times of 100 ms) and 2.0 s
(exposure times of 300 ms) in the Fe XIV and Fe X emission lines,
respectively. The analysis of the data indicates intensity variations at
some locations with period of strongest power around 27 s for the green
line and 20 s for the red line. These results confirm earlier findings
of variations in the continuum intensity with periods in the range
of 5 to 56 s by Singh et al. (Solar Phys.170, 235, 1997). The wavelet
analysis has been used to identify significant intensity oscillations
at all pixels within our field of view. Significant oscillations with
high probability estimates were detected for some locations only. These
locations seem to follow the boundary of an active region and in the
neighborhood, rather than within the loops themselves. These intensity
oscillations may be caused by fast magneto-sonic waves in the solar
corona and partly account for heating of the plasma in the corona.
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Title: Identification of SrF molecular lines in the spectrum of
sunspot umbra
Authors: Sriramachandran, P.; Shanmugavel, R.; Bagare, S. P.;
Rajamanickam, N.
2009Ap&SS.323...41S Altcode: 2009Ap&SS.tmp...70S
A high resolution spectrum of a sunspot umbra is used for identification
of rotational lines due to (0, 0) band of the A <SUP>2</SUP>Π- X
<SUP>2</SUP>Σ<SUP>+</SUP> system and (0, 0), (1, 1), and (2, 2) bands
of the B <SUP>2</SUP>Σ<SUP>+</SUP>- X <SUP>2</SUP>Σ<SUP>+</SUP> system
of the molecule SrF. The published sunspot umbral spectrum obtained with
Fourier Transform Spectrometer and solar telescope of National Solar
Observatory/National Optical Astronomy Observatory at Kitt Peak was
used for the study. The new identification of more than 200 SrF lines
in the umbral spectrum confirms that this molecule accounts for the
majority of lines in the spectral range 15050 to 15360 cm<SUP>-1</SUP>
and 17240 to 17300 cm<SUP>-1</SUP>. Equivalent widths have been measured
for well-resolved lines of these bands and the effective rotational
temperatures have been estimated for which the presence is confirmed.
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Title: Identification of CrH and CrD Molecular Lines in the Sunspot
Umbral Spectrum
Authors: Viswanathan, B.; Shanmugavel, R.; Bagare, S. P.; Rajamanickam,
N.; Sriramachandran, P.
2009SoPh..257..261V Altcode:
High-resolution Fourier transform spectrometer sunspot umbral spectra
obtained at the National Solar Observatory/Kitt Peak were used to
identify molecular rotational lines arising from the infrared band
systems of CrH and CrD molecules. Measurement of the equivalent width
used the Gaussian-profile approximation method, which is suitable
especially for faint lines. Equivalent widths are measured for an
adequate number of best lines of the A - X (0,0) band of CrH and the
A - X (0,0;1,0) bands of CrD and, thereby, the effective rotational
temperatures are estimated.
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Title: On the search for BF, BH and BS molecular lines in sunspot
spectra
Authors: Karthikeyan, B.; Bagare, S. P.; Rajamanickam, N.; Raja, V.
2009APh....31....6K Altcode:
A search has been carried out for the presence of rotational lines
of boron containing diatomic molecules BF, BH and BS in the high
resolution Fourier Transform Spectra of sunspots observed at the
National Solar Observatory in Kitt Peak. The spectra were examined
for a large number of rotational lines due to nine bands of BF,
ten bands of BH and eight bands of BS in the range 9600 25,500
cm<SUP>-1</SUP>. The presence of the lines due to six bands of BF and
five bands of BS is confirmed. However, the presence of BH is found
to be questionable. Equivalent widths have been measured for well
resolved lines of BF and BS and effective rotational temperatures have
been estimated.
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Title: Presence of LaO, ScO and VO Molecular Lines in Sunspot
Umbral Spectra
Authors: Sriramachandran, P.; Bagare, S. P.; Rajamanickam, N.;
Balachandrakumar, K.
2008SoPh..252..267S Altcode: 2008SoPh..tmp..161S
High-resolution Fourier Transform Spectrometer sunspot umbral
spectra of the National Solar Observatory/National Optical Astronomy
Observatory at Kitt Peak were used to detect rotational lines from
19 electronic transition bands of the molecules LaO, ScO and VO,
in the wavenumber range of 11 775 to 20 600 cm<SUP>−1</SUP>. The
presence of lines from the following transitions is confirmed:
A<SUP>2</SUP>Π<SUB>r1/2</SUB> - X<SUP>2</SUP>Σ<SUP>+</SUP>(0, 0; 0,
1), A<SUP>2</SUP>Π<SUB>r3/2</SUB> - X<SUP>2</SUP>Σ<SUP>+</SUP>(1,
0), B<SUP>2</SUP>Σ<SUP>+</SUP> - X<SUP>2</SUP>Σ<SUP>+</SUP>(0,
0; 0, 1; 1, 0) and C<SUP>2</SUP>Π<SUB>r1/2</SUB>
- A'<SUP>2</SUP>Δ<SUB>r3/2</SUB>(0, 0; 1, 1) of LaO;
A<SUP>2</SUP>Π<SUB>r3/2</SUB> - X<SUP>2</SUP>Σ<SUP>+</SUP>(0, 0),
A<SUP>2</SUP>Π<SUB>r1/2</SUB> - X<SUP>2</SUP>Σ<SUP>+</SUP>(0, 0) and
B<SUP>2</SUP>Σ<SUP>+</SUP> - X<SUP>2</SUP>Σ<SUP>+</SUP>(0, 0) of ScO;
and C<SUP>4</SUP>Σ<SUP>−</SUP> - X<SUP>4</SUP>Σ<SUP>−</SUP>(0,
1; 1, 0; 0, 2) and (2, 0) of VO. However, the presence of
A<SUP>2</SUP>Π<SUB>r3/2</SUB> - X<SUP>2</SUP>Σ<SUP>+</SUP>(0, 0) and
C<SUP>2</SUP>Π<SUB>r3/2</SUB> - A'<SUP>2</SUP>Δ<SUB>r5/2</SUB>(0,
0; 1, 1) of LaO and C<SUP>4</SUP>Σ<SUP>−</SUP> -
X<SUP>4</SUP>Σ<SUP>−</SUP>(0, 0) of VO are found to be doubtful
because the lines are very weak, and detections are difficult owing to
heavy blending by strong rotational lines of other molecules. Equivalent
widths are measured for well-resolved lines and, thereby, the effective
rotational temperatures are estimated for the systems for which the
presence is confirmed.
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Title: Identification of Beryllium Hydride Isotopomer Lines in
Sunspot Umbral Spectra
Authors: Shanmugavel, R.; Bagare, S. P.; Rajamanickam, N.; Balachandra
Kumar, K.
2008SerAJ.176...51S Altcode:
A high resolution spectrum of FTS sunspot umbra of NSO/Kitt Peak was
used to conduct a search for the molecular absorption lines due to BeH,
BeD and BeT isotopomers. Analysis led to estimates of identification
of the molecular lines of bands A - X (0,0), (1,1) and (2,2) for
BeH, A - X (0,0), (1,1), (2,2) and (3,3) for BeD and of A - X (0,0),
(1,1) and (2,2) for BeT. Among the identified lines, those which are
well resolved were selected for measurements to calculate equivalent
widths. The values of effective rotational temperature T were estimated
for bands A - X(1,1) and (2,2) of BeH, A - X(1,1) of BeD and A - X(2,2)
of BeT to be 4228K, 4057K, 3941K and 3243K respectively.
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Title: Evaluation of Astrophysically Useful Parameters for LaO
Molecule
Authors: Sriramachandran, Ponsamy; Shanmugavel, Ramachandran;
Rajamanickam, Narayanan; Bagare, Somashekar Pundalikarao
2008RoAJ...18...21S Altcode:
No abstract at ADS
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Title: On the Franck-Condon Factors and r-Centroids of the
Astrophysically Interesting Molecule CS
Authors: Karthikeyan, B.; Raja, V.; Rajamanickam, N.; Bagare, S. P.
2007SerAJ.175...25K Altcode:
In molecular astrophysics, the Franck-Condon (FC) factors
and r-centroids are essential for the interpretation of spectral
intensities in terms of emitting astrophysical source conditions. They
have been evaluated for the band systems a <SUP>3</SUP>Π<SUB>r</SUB> -
X <SUP>1</SUP>Σ<SUP>+</SUP>, d <SUP>3</SUP>Δ<SUB>i</SUB><SUP>n</SUP>
- X <SUP>1</SUP>Σ<SUP>+</SUP>, e <SUP>3</SUP>Σ<SUP>-</SUP> -
X <SUP>1</SUP>Σ<SUP>+</SUP>, A' <SUP>1</SUP>Σ<SUP>+</SUP> - X
<SUP>1</SUP>Σ<SUP>+</SUP> and d <SUP>3</SUP>Δ<SUB>i</SUB><SUP>n</SUP>
- a <SUP>3</SUP>Π<SUB>r</SUB> of astrophysical molecule CS. The
physical and astrophysical significances of our evaluated FC factors
and r-centroids are discussed. The FC factor values of a - X system
have been compared with the values of FC factors reported by Reddy et
al. (2003).
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Title: Some useful data for the astrophysical molecules AlS and BS
Authors: Karthikeyan, B.; Rajamanickam, N.; Bagare, S. P.
2007APh....27..382K Altcode:
The vibronic (vibration-electronic) transition probability parameters
such as Franck-Condon (FC) factors and r-centroids of diatomic
molecular species could be useful in the identification of molecular
lines and in the estimation of relative abundance of the species in
astrophysical sources. In this study, they have been evaluated for
the electronic transitions A2Σ<SUP>+</SUP>→X2Σ<SUP>+</SUP>
and A2Σ<SUP>+</SUP>→X2Σ<SUP>+</SUP> of AlS and
C2Π<SUB>r</SUB>→X2Σ<SUP>+</SUP>, E2Σ<SUP>+</SUP>→X2Σ<SUP>+</SUP>
and B2Σ<SUP>+</SUP>→A2Π<SUB>i</SUB> of BS molecules, by a numerical
integration procedure using a suitable potential. The physical and
astrophysical significances of our evaluated FC factors and r-centroids
have also been discussed, which would be helpful in the prediction
of the presence of AlS and BS molecules in umbral sunspots and other
celestial bodies.
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Title: Astrophysically Useful Parameters for Certain Band Systems
of BeH, BeD and BeT Molecules
Authors: Shanmugavel, R.; Bagare, S. P.; Rajamanickam, N.
2006SerAJ.173...83S Altcode:
The vibronic (vibration-electronic) transition probability parameters
such as Franck-Condon (FC) factors and r-centroids of diatomic molecular
species could be useful in the identification of molecular bands and
in the estimation of relative abundance of the emitted species in
astrophysical sources. In this study, they have been evaluated for
the electronic transitions A(2}Π_{r) - X(2}Σ({+)) , B(2}Π_{r) -
X(2}Σ({+)) and C(2}Σ({+)) - X(2}Σ({+)) systems of BeH, A(2}Π_{r) -
X(2}Σ({+)) and C(2}Σ({+)) - X(2}Σ({+)) system of BeD and A(2}Π_{r)
- X(2}Σ({+)) system of BeT molecules using a suitable potential.
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Title: Astrophysically Useful Parameters for Some Vibronic Transitions
of AlH and BH
Authors: Karthikeyan, B.; Raja, V.; Rajamanickam, N.; Bagare, S. P.
2006Ap&SS.306..231K Altcode: 2006Ap&SS.tmp..575K
For molecular identification in astrophysical sources, an astrophysicist
needs some spectroscopic parameters such as dissociation energy,
vibrational or rotational temperature of the source, band or
line wavelengths, transition probability parameters, etc. The
Franck-Condon(FC) factors are proportional to the transition
probabilities. In this study, the FC factors and r-centroids for
the vibronic (vibration-electronic) transitions C <SUP>1</SUP>
Σ <SUP>+</SUP> → X <SUP>1</SUP> Σ <SUP>+</SUP> of aluminium
hydride (AlH), b <SUP>3</SUP> Σ <SUP>( -)</SUP> → a <SUP>3</SUP>
Π, C <SUP>1</SUP> Σ <SUP>+</SUP> → A <SUP>1</SUP> Π &
C <SUP>‧1</SUP> Δ → Δ <SUP>1</SUP> Π of boron hydride (BH)
have been evaluated and the results are presented in tables which
include band origin/head wavelengths. The physical & astrophysical
significances of our evaluated FC factors & r-centroids have been
discussed and the possible presence of AlH in sunspot umbral spectra
is also predicted.
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Title: Evaluation of astrophysically useful parameters for HD molecule
Authors: Karthikeyan, B.; Rajamanickam, N.; Bagare, S. P.
2006APh....26..186K Altcode:
The spectrum of HD molecule is the testing ground of both refined
calculations and experimental techniques and its excited states are of
considerable relevance to chemistry and astrophysics. In this study,
the Franck-Condon (FC) factors and r-centroids are evaluated for the
bands of d3Π-a3Σg+, e 3Σu+-a3Σg+ and I 1Π-B1Σu+ transitions of
HD molecule. The evaluation is done by numerical integration procedure
using a suitable potential. The physical and astrophysical significance
of the estimated FC factors and r-centroids are also discussed.
---------------------------------------------------------
Title: Evaluation of Astrophysically Useful Parameters for Strontium
Monohydride and Deuteride
Authors: Sri Ramachandran, P.; Rajamanickam, N.; Bagare, S. P.
2006SerAJ.172...13S Altcode:
The Franck-Condon factors and r-centroids which are very closely
related to transition probabilities, have been evaluated by the more
reliable numerical integration procedure for the band systems B^{2}sum -
X^{2}sum, C^{2}sum -X^{2}sum and F^{2}sum - X^{2}sum of astrophysical
molecules strontium monohydride and strontium deuteride using an
adequate potential. The Franck-Condon factors are more intense,
particularly for the Δ ν = 0 bands, for all the systems examined
here. Thus the bands of the molecules are expected to be present in
sunspot spectra, SC-stars, cool M-giant stars and other prominent
astrophysical sources.
---------------------------------------------------------
Title: Identification of AlF Molecular Lines in Sunspot Umbral Spectra
Authors: Bagare, S. P.; Kumar, K. Balachandra; Rajamanickam, N.
2006SoPh..234....1B Altcode:
High resolution FTS sunspot umbral spectra from NSO/Kitt Peak were
used to detect rotational lines due to 11 electronic transitions
of the molecule AlF, in the wavelength region 4400 - 9000 Å. The
presence of lines due to bands C - A (0,0), (0,1), (0,2) and (1,2),
D - A (0,0) and (0,1), F - A (0,0), G - A (0,0), and F - B (0,0) is
confirmed. Further, the presence of lines due to C - A (1,0) and (1,1)
transitions is treated as doubtful because of heavy blending in the
region, by rotational lines of TiO. Among the identified lines, those
which are well resolved were selected for measurement of equivalent
widths. The measured values for the bands D - A (0,0) and F - A (0,0)
were used to estimate the respective effective rotational temperatures
to be 1240 ± 120 K and 2390 ± 400 K.
---------------------------------------------------------
Title: Formation and Observations of Shadow Bands During the Total
Solar Eclipse of November 23, 2003 Near Maitri, Antarctic
Authors: Vats, Hari Om; Bagare, S. P.; Bhandari, S. M.
2006aogs....2..361V Altcode:
The phenomenon of shadow bands takes place due to the scattering of
sunlight by the irregularities in the local atmosphere. Observation of
shadow bands were made just before and after the total solar eclipse
(TSE) on November 23, 2003 near the Indian Antarctic station Maitri
(long. 11°45″E and lat. 70°45″S). The formation and observations
of shadow bands during this TSE are presented. The results of
correlation analysis show that the correlation (1) falls to half at
separation of 35 cm in horizontal direction; and (2) also at ∼100ms
time lag. The power spectrum of the shadow band fluctuations had
a power law distribution (spectral index ∼ -2) which is different
from earlier eclipse observations reported in the literature. However,
it closely resembles theoretical predictions of the extended screen
scintillation theory.
---------------------------------------------------------
Title: Estimation of Astrophysically Useful Parameters for SnF and
ScF Molecules
Authors: Sri Ramachandran, Ponsamy; Shanmugavel, Ramachandran;
Rajamanickam, Narayanan; Bagare, Somashekar Pundalikarao
2006RoAJ...16..123S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Franck-Condon factors and r-centroids for certain band systems
of astrophysical molecules SrF and ScF
Authors: Ramachandran, P. Sri; Rajamanickam, N.; Bagare, S. P.; Kumar,
Bala Chandra
2005Ap&SS.295..443R Altcode:
The Franck-Condon factors and r-centroids, which are very closely
related to vibrational transition probabilities, have been evaluated
by the more reliable numerical integration procedure for the bands
of B <SUP>2</SUP>∑<SUP>+</SUP> - X <SUP>2</SUP>∑<SUP>+</SUP>, F
<SUP>2</SUP>∑<SUP>+</SUP> - X <SUP>2</SUP>∑<SUP>+</SUP> systems of
SrF and C <SUP>1</SUP>∑<SUP>+</SUP> - X <SUP>1</SUP>∑<SUP>+</SUP>, G
<SUP>1</SUP>Π - X <SUP>1</SUP>∑<SUP>+</SUP> systems of ScF molecules
of astrophysical interest, using a suitable potential.
---------------------------------------------------------
Title: Molecular parameters for D, E, F, and G-A band systems of
the astrophysically significant molecule AlF
Authors: Balachandra Kumar, K.; Bagare, S. P.; Rajamanickam, N.
2004Ap&SS.289....9B Altcode:
Franck-Condon factors andr-centroids, which are a measure oftransition
probabilities, have been evaluated by a numerical integration procedure
for the bands of D<SUP>1</SUP>Δ,E<SUP>1</SUP>Π, F<SUP>1</SUP>Π and
G<SUP>1</SUP>Σ<SUP>+</SUP> A<SUP>1</SUP>Π systems of AlFmolecule.The
species has been observed incircumstellar envelopes around AGB
stars and spectral studies report its presence in sunspots. The
molecularparameters evaluated are necessary forstudying the physical
and dynamical properties of these sources.
---------------------------------------------------------
Title: Franck-Condon factors and /r-centroids for a number of band
systems of the astrophysical molecule AlF
Authors: Balachandra Kumar, K.; Rajamanickam, N.; Bagare, S. P.;
Fernandez Gomez, M.; Lopez Gonzalez, J. J.
2003APh....20...67B Altcode: 2003APh....20...67K
Franck-Condon factors and r-centroids, which are very closely
related to transition probabilities, have been evaluated by the
more reliable numerical integration procedure for the bands of
B <SUP>1</SUP>Σ<SUP>+</SUP>- X <SUP>1</SUP>Σ<SUP>+</SUP>,
C <SUP>1</SUP>Σ<SUP>+</SUP>- X <SUP>1</SUP>Σ<SUP>+</SUP>,
c <SUP>3</SUP>Σ<SUP>+</SUP>- b <SUP>3</SUP>Σ<SUP>+</SUP>, f
<SUP>3</SUP>Π- b <SUP>3</SUP>Σ<SUP>+</SUP>, F <SUP>1</SUP>Π-
B <SUP>1</SUP>Σ<SUP>+</SUP> and G<SUP>1</SUP>Σ<SUP>+</SUP>- B
<SUP>1</SUP>Σ<SUP>+</SUP> systems of the AlF molecule. The species
has been observed in circumstellar envelope around Asymptotic Giant
Branch stars and is likely to be present in the umbral atmosphere. The
molecular parameters, necessary for studying the physical and dynamical
properties of the above said sources, are evaluated in the present work.
---------------------------------------------------------
Title: Transition probability parameters for certain band systems
of astrophysical molecule GeO
Authors: Rajamanickam, N.; Shanmugavel, R.; Prithivikumaran, N.;
Palaniselvam, T.; Bagare, S. P.
2003APh....19..299R Altcode:
The transition probability parameters, Franck-Condon factors and
/r-centroids, have been evaluated using the most reliable numerical
integration procedure for the bands of E<SUP>1</SUP>Σ<SUP>+</SUP>,
F<SUP>1</SUP>Σ<SUP>+</SUP>, /GΣ, HΠ, JΣ-X<SUP>1</SUP>Σ<SUP>+</SUP>
systems of astrophysical molecule GeO, using a suitable potential.
---------------------------------------------------------
Title: Digitization of Kodaikanal Data
Authors: Singh, Jagdev; Muneer, S.; Bagare, S. P.; Rangarajan, K. E.;
Ramesh, K. B.; Varghese, B. A.; Samson, J. P. A.; Devendran, P.;
Hariharan, G.
2003BASI...31..111S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Transition probability parameters for the band systems G,
H and I-B of astrophysical molecule PO
Authors: Rajamanickam, N.; Balachandrakumar, K.; Shanmugavel, R.;
Sriramachandran, P.; Nagarajan, K.; Bagare, S. P.
2003Ap&SS.284.1195R Altcode:
The transition probability parameters, Franck - Condon factors and
r-centroids, have been evaluated by the more reliable numerical
integration procedure for the bands of G, H and I-B systems of
astrophysical molecule PO, using a suitable potential.
---------------------------------------------------------
Title: The Distribution of the Quiet Sun Photospheric Magnetic Flux
Authors: Srikanth, R.; Singh, Jagdev; Bagare, S. P.
2002BASI...30..871S Altcode:
A gradient-based tessellating algorithm is used to study the magnetic
field structure of the quiet Sun photosphere using SoHO full disk
magnetograms. We find that the field is not uniformly distributed,
but parcelled into flux concentrations. Both the flux and size of
the concentrations are found to be described by broad, asymmetric
distribution functions. Their mean absolute flux and size are
found to be about 1.4 x 1018 mx and 6.1 Mm for both polarities in
unsmoothed magnetograms at 5 gauss threshold. These values represent
a weighted average for both network- and intranetwork magnetic fields,
since the present method cannot currently distinguish between the two
regions. Both flux and size distributions become more symmetric and less
peaked in response to smoothing of images. Extrapolating this trend to
sub-resolution scale, we note a linear decrease in size but a rapid
increase in the mean absolute field strength, with asymptotic values
of about 400 km and 50 gauss. This exercise shows that the true field
strengths of quiet magnetic elements are higher and their size smaller
than usually inferred from observations. This is because observation
of mixed polarity regions under finite resolution causes the observed
flux to be smeared out and apparently modified. Therefore, this flux
cannot be interpreted independently of the geometric structure and
flux distribution of the concentrations.
---------------------------------------------------------
Title: Transition Probability Parameters for Certain Band Systems
of the Astrophysical Molecule PO
Authors: Balachandra Kumar, K.; Raja, V.; Nagarajan, K.; Bagare,
S. P.; Rajamanickam, N.
2002BaltA..11..529B Altcode: 2002OAst...11..529B
The transition probability parameters, Franck-Condon factors and
r-centroids have been evaluated by a new more reliable numerical
integration procedure for the bands of the PO molecule in the
ultraviolet region (1800--2900 Å). These molecules are likely to be
present in the atmospheres of cool stars and comets.
---------------------------------------------------------
Title: Transition probabilities and dissociation energy of
astrophysical molecule CoH
Authors: Prithivikumaran, N.; Fernandez Gomez, M.; Lopez Gonzalez,
J. J.; Bagare, S. P.; Rajamanickam, N.
2002Ap&SS.280..319P Altcode:
The Franck-Condon (FC) factors (transition probabilities) and
r-centroids have been evaluated by the reliable numerical integration
procedure for the bands of the A^3 φ_4 --> X^3 φ_4 system of
astrophysical molecule CoH, using a suitable potential. The dissociation
energy D^0_0 = 2.5 +/- 0.05 eV for the electronic ground state of CoH
has been estimated by fitting Hulburt-Hirschfelder function to the
experimental potential energy curve, using the correlation coefficient.
---------------------------------------------------------
Title: On the relation between magnetic field strength and Wilson
depression in sunspots
Authors: Bagare, S. P.; Gupta, S. S.
1998BASI...26..197B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Detection of Short-Period Coronal Oscillations during the
Total Solar Eclipse of 24 October, 1995
Authors: Singh, Jagdev; Cowsik, R.; Raveendran, A. V.; Bagare, S. P.;
Saxena, A. K.; Sundararaman, K.; Krishan, Vinod; Naidu, Nagaraja;
Samson, J. P. A.; Gabriel, F.
1997SoPh..170..235S Altcode:
An experiment to search for short-period oscillations in the solar
corona was conducted during the total solar eclipse of 1995 October 24
at Kalpi, India. The intensity in the continuum, centred around 5500
Å and with a passband having a half-width of 240 Å, was recorded
at a counting rate of 20 Hz using a thermoelectric-liquid cooled
photomultiplier. The power-spectrum analysis of the data reveals
that most of the power is contained in 6 frequencies below 0.2 Hz. A
least-square analysis gives the periods of the 6 frequency components
to be 56.5, 19.5, 13.5, 8.0, 6.1, and 5.3 s. These oscillations are
found to be sinusoidal, and their amplitudes are found to lie in the
rangełinebreak 0.2-1.3% of the coronal brightness. Assuming these
oscillations to be fast magnetosonic modes, the calculations indicate
the availability of enough flux for the heating of the active regions
in the solar corona.
---------------------------------------------------------
Title: Observation of intensity oscillations in corona during the
total solar eclipse of October 24, 1995.
Authors: Singh, J.; Cowsik, R.; Raveendran, A. V.; Bagare, S. P.;
Saxena, A. K.; Sundararaman, K.; Naidu, N.; Samson, J. P. A.;
Gabriel, F.
1997KodOB..13....5S Altcode:
An experiment to search for short-period oscillations in the solar
corona was conducted during this solar eclipse. The power spectrum
analysis of the data reveals that most of the power is contained in
6 frequencies below 0.2 Hz. A least-square analysis gives periods of
the 6 frequency components to be 56.5, 19.5, 13.5, 8.0, 6.1 and 5.3 sec.
---------------------------------------------------------
Title: Search for hydrogen-alpha emitting cool pockets in corona
during the total solar eclipse of October 24, 1995.
Authors: Bagare, S. P.; Cowsik, R.; Singh, J.; Raju, K. P.; Saxena,
A. K.; Samson, J. P. A.; Naidu, B. N.
1997KodOB..13...53B Altcode:
Narrow pass band H-alpha filtergrams were obtained during totality
at Kalpi, to look for cool pockets of H-alpha emission in the corona
first observed by Bappu and Bhattacharyya during the 1970 Mexican
eclipse observations. A 1k XIk liquid cooled CCD camera was used to
record the corona using a 2 cm solar image. No evidence of any H-alpha
emitting pockets was found in the observed part of the corona.
---------------------------------------------------------
Title: Broad band photometry of solar corona during the total solar
eclipse of October 24, 1995.
Authors: Bagare, S. P.; Aleem, P. S. M.; Singh, J.; Saxena, A. K.
1997KodOB..13...55B Altcode:
A 30 cm coelostat, a red broad band filter, and a 15 cm objective
providing an f/15 beam were used to obtain high resolution pictures
of the white light solar corona. In one of the frames, the presence
of a loop structure is recorded with its top around 2 R<SUB>sun</SUB>,
in the near north polar region. The nearest YOHKOH soft X-ray picture
shows the presence of a coronal hole with its border apparently beneath
the loop structure. The preliminary results are discussed.
---------------------------------------------------------
Title: A study of inner solar corona during total solar eclipse of
October 24, 1995.
Authors: Saxena, A. K.; Cowsik, R.; Lancelot, J. P.; Samson, J. P. A.;
Bagare, S. P.; Ismail, R.
1997KodOB..13...11S Altcode:
An experiment to study the intensity variations in the inner corona
was setup at Kalpi, in Uttar Pradesh, during the total solar eclipse
of October 24, 1995. The details of the experiment and the preliminary
results are presented.
---------------------------------------------------------
Title: Day-time seeing observations at Kodaikanal Tower Telescope
Authors: Bagare, S. P.
1995BASI...23...57B Altcode:
A limb monitor was fabricated and used for the observation of seeing
conditions at the Solar tower telescope of Kodaikanal observatory. We
describe the instrument and report the results obtained on image
stability, intermittency of good moments, their durations and utility
in adopting a frame selection technique at the telescope. We discuss
the observed clustering of moments with good image steadiness and use
it to estimate the cell size range of a dominant scale of atmospheric
turbulence during the observations.
---------------------------------------------------------
Title: Observational evidence for mesogranular cells in the solar
photosphere.
Authors: Bagare, S. P.; Sivaraman, K. R.
1991BASI...19..207B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: On the Location of Footpoints of Sub-Arc Magnetic Structures
in the Quiet Solar Photosphere
Authors: Sivaraman, K. R.; Bagare, S. P.; November, L. J.
1990IAUS..142..192S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Transient activity in the loop prominence system of a flare
active region
Authors: Bagare, S. P.; Nagabhushana, B. S.; Aleem, P. S. M.
1989BASI...17..102B Altcode:
Solar limb observations of the activity in a loop prominence system
associated with an active region were obtained on February 2, 1984. The
activity was observed for a total duration of over seven hours of which
the maximum phase lasted for about an hour. From a series of Ca II K
prominence spectroheliograms taken during this phase, the individual
loops appear to experience a sequence of activity; the brightening of
kernel, brightening of portions of the loop, motion of the enhanced
brightenings along the legs of the loop and a diffuse appearance of
the loop at the end phase. The details of these phenomena and other
associated activity are described.
---------------------------------------------------------
Title: Astrometry of Comet Halley during the 1985-86 apparition
Authors: Bagare, S. P.; Scaria, K. K.
1988BASI...16...78B Altcode:
Photographs of Comet Halley were obtained using the 1-m telescope of the
Vainu Bappu Observatory, Kavalur, during the 1985-86 apparition, and
astrometric measurements carried out. The details of the observations
and the measurement technique adopted are given. The observed apparent
positions of the comet are compared with the predicted values. The
results agree well with the revised predictions.
---------------------------------------------------------
Title: Chromospheric CA II K-Line Variations in the Sun as a Star
over a Solar Cycle
Authors: Sivaraman, K. R.; Singh, Jagdev; Bagare, S. P.; Gupta, S. S.
1987ApJ...313..456S Altcode:
The disk-averaged Ca II K profiles obtained at the Kodaikanal solar
tower telescope for the period 1969-1984 are used to study the
chromospheric variations in the sun as a star. The 1A index shows
increases of 18 and 28 percent during the 20th and 21st cycles,
respectively. The corresponding enhancements in the central intensity
in the K line are 24 and 40 percent, respectively. The other K-line
parameters, such as the intensity of K2 emission, K-line widths,
and the V/R asymmetry, all show systematic variations over the solar
cycle. Although the plage seems to be responsible for almost all the
variations noticed, the participation of the bright points and the
network may have to be taken into consideration to account fully for
all the solar cycle-related changes.
---------------------------------------------------------
Title: Calibration on the Sun for Stellar Magnetic Fields
Authors: Sivaraman, K. R.; Bagare, S. P.; Gupta, S. S.; Kariyappa, R.
1987LNP...291...47S Altcode: 1987csss....5...47S; 1987LNP87.291...47S
The intimate association between the surface magnetic fields and the
Ca II K line emission known to exist on the sun, holds a promise for
using this property to detect the presence of global magnetic fields on
sun - like stars. We have obtained a large number of K line profiles
over a variety of plages on the sun and related the 1A emission flux
centred at the K3 minimum for these profiles with the corresponding
values of the longitudinal component of the photospheric magnetic
field. This provides a calibration for detecting and estimating the
surface magnetic fields on stars that show K emission.
---------------------------------------------------------
Title: Solar flare of 1982 April 14
Authors: Bagare, S. P.
1985BASI...13..394B Altcode:
The author has obtained a good time sequence of spectroheliograms and
spatial sequence spectra in the K-line of Ca II using the Kodaikanal
tower telescope. He has derived the two dimensional pattern of the mass
motions of the plasma associated with the flare at this level in the
solar atmosphere. He finds that significant mass motions are practically
confined to the two ribbons that developed soon after the flaring event.
---------------------------------------------------------
Title: Luminosity variations in the Ca II K lines and the solar cycle.
Authors: Sivaraman, K. R.; Singh, J.; Bagare, S. P.; Gupta, S. S.
1985BASI...13Q..79S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Brightness, polarization and electron density of the solar
corona of 1980 February 16
Authors: Sivaraman, K. R.; Jayachandran, M.; Scaria, K. K.; Babu,
G. S. D.; Bagare, S. P.; Jayarajan, A. P.
1984JApA....5..149S Altcode:
During the eclipse of 1980 February 16 the authors photographed the
solar corona at an effective wavelength of 6300 Å. Using a quadruple
camera coronal pictures were obtained in polarized light for four
polaroid orientations. These observations are used to derive the coronal
brightness and polarization and from these the electron densities in
the corona out to a distance of about 2.5 R_sun; from the centre of
the disc. The coronal brightness matches well with that of the corona
of 1958 October 12.
---------------------------------------------------------
Title: Solar Flare of April 14, 1982
Authors: Bagare, S. P.; Sivaraman, K. R.
1983ICRC....4...20B Altcode: 1983ICRC...18d..20B
No abstract at ADS
---------------------------------------------------------
Title: Broad-band photometry of the corona.
Authors: Scaria, K. K.; Bagare, S. P.; Jayarajan, A. P.
1981otse.conf...35S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Dissociation energy for the ground state of AlO from true
potential energy curve.
Authors: Murthy, N. S.; Bagare, S. P.; Murthy, B. N.
1978JQSRT..19..455M Altcode:
No abstract at ADS
