Author name code: bagare ADS astronomy entries on 2022-09-14 author:"Bagare, Somashekar Pundalikarao" ------------------------------------------------------------------------ Title: An attempt of identification of barium hydride molecular lines in sunspot umbral spectra Authors: Karthikeyan, B.; Shanmugapriya, G.; Rajamanickam, N.; Bagare, S. P. Bibcode: 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-1 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 2Π1/2 - X 2Σ ((0,0), (1,1), (2,2), (1,0), (2,1)), A 2Π3/2 - X 2Σ ((0,0), (1,1), (2,2)), B 2Π1/2 - X 2Σ (0,0), B 2Π3/2 - X 2Σ (0,0), C 2Σ - X 2Σ ((1,1), (1,0), (2,2), (2,1), (3,2)) and D 2Σ - X 2Σ ((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 2Π1/2 - X 2Σ, (0,0) (1,1) and (2,2) of A 2Π3/2 - X 2Σ, B 2Π1/2 - X 2Σ (0,0) and B 2Π3/2 - X 2Σ (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. Title: Examining Barium Deuteride Molecules in Sunspots Authors: Karthikeyan, B.; Shanmugapriya, G.; Rajamanickam, N.; Bagare, S. P. Bibcode: 2018RNAAS...2...21K Altcode: 2018RNAAS...2a..21K No abstract at ADS Title: Abnormal rotation rates of sunspots and durations of associated flares Authors: Suryanarayana, G. S.; Hiremath, K. M.; Bagare, S. P.; Hegde, M. Bibcode: 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.
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.
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.
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.
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. 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. Bibcode: 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 A1Σ-X1Σ+ system and three bands of the A'1Π-X1Σ+ 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−1. 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. 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. Bibcode: 2015AdAst2015E...1B Altcode: No abstract at ADS 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. Bibcode: 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. Title: Solar Astronomy at High Altitude Authors: Hasan, S. S.; Bagare, S. P.; Rangarajan, K. E. Bibcode: 2014PINSA..80..815H Altcode: No abstract at ADS Title: Dynamic responses of sunspots to their ambient magnetic configuration Authors: Bagare, S. P. Bibcode: 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. Title: On the Rotational Temperature of AlH in Sunspots Authors: Karthikeyan, B.; Rajamanickam, N.; Bagare, S. P. Bibcode: 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 1Π - X 1Σ+ 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−1 (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. Title: Solar Physics at the Kodaikanal Observatory: A Historical Perspective Authors: Hasan, S. S.; Mallik, D. C. V.; Bagare, S. P.; Rajaguru, S. P. Bibcode: 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. Title: Aerosol optical properties retrieved using Skyradiometer at Hanle in western Himalayas Authors: Verma, Neeharika; Bagare, S. P.; Ningombam, Shantikumar Singh; Singh, Rajendra B. Bibcode: 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. Title: Revisit of the Classic Wilson Effect Authors: Bagare, S. P. Bibcode: 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. 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. Bibcode: 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. 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. Bibcode: 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. Title: Identification of SrF molecular lines in the spectrum of sunspot umbra Authors: Sriramachandran, P.; Shanmugavel, R.; Bagare, S. P.; Rajamanickam, N. Bibcode: 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 2Π- X 2Σ+ system and (0, 0), (1, 1), and (2, 2) bands of the B 2Σ+- X 2Σ+ 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-1 and 17240 to 17300 cm-1. 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. 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. Bibcode: 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. Title: On the search for BF, BH and BS molecular lines in sunspot spectra Authors: Karthikeyan, B.; Bagare, S. P.; Rajamanickam, N.; Raja, V. Bibcode: 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-1. 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. Title: Presence of LaO, ScO and VO Molecular Lines in Sunspot Umbral Spectra Authors: Sriramachandran, P.; Bagare, S. P.; Rajamanickam, N.; Balachandrakumar, K. Bibcode: 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−1. The presence of lines from the following transitions is confirmed: A2Πr1/2 - X2Σ+(0, 0; 0, 1), A2Πr3/2 - X2Σ+(1, 0), B2Σ+ - X2Σ+(0, 0; 0, 1; 1, 0) and C2Πr1/2 - A'2Δr3/2(0, 0; 1, 1) of LaO; A2Πr3/2 - X2Σ+(0, 0), A2Πr1/2 - X2Σ+(0, 0) and B2Σ+ - X2Σ+(0, 0) of ScO; and C4Σ− - X4Σ−(0, 1; 1, 0; 0, 2) and (2, 0) of VO. However, the presence of A2Πr3/2 - X2Σ+(0, 0) and C2Πr3/2 - A'2Δr5/2(0, 0; 1, 1) of LaO and C4Σ− - X4Σ−(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. Title: Identification of Beryllium Hydride Isotopomer Lines in Sunspot Umbral Spectra Authors: Shanmugavel, R.; Bagare, S. P.; Rajamanickam, N.; Balachandra Kumar, K. Bibcode: 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. Title: Evaluation of Astrophysically Useful Parameters for LaO Molecule Authors: Sriramachandran, Ponsamy; Shanmugavel, Ramachandran; Rajamanickam, Narayanan; Bagare, Somashekar Pundalikarao Bibcode: 2008RoAJ...18...21S Altcode: No abstract at ADS 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. Bibcode: 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 3Πr - X 1Σ+, d 3Δin - X 1Σ+, e 3Σ- - X 1Σ+, A' 1Σ+ - X 1Σ+ and d 3Δin - a 3Πr 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). Title: Some useful data for the astrophysical molecules AlS and BS Authors: Karthikeyan, B.; Rajamanickam, N.; Bagare, S. P. Bibcode: 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+→X2Σ+ and A2Σ+→X2Σ+ of AlS and C2Πr→X2Σ+, E2Σ+→X2Σ+ and B2Σ+→A2Πi 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. Title: Astrophysically Useful Parameters for Certain Band Systems of BeH, BeD and BeT Molecules Authors: Shanmugavel, R.; Bagare, S. P.; Rajamanickam, N. Bibcode: 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. Title: Astrophysically Useful Parameters for Some Vibronic Transitions of AlH and BH Authors: Karthikeyan, B.; Raja, V.; Rajamanickam, N.; Bagare, S. P. Bibcode: 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 1 Σ + → X 1 Σ + of aluminium hydride (AlH), b 3 Σ ( -) → a 3 Π, C 1 Σ + → A 1 Π & C ‧1 Δ → Δ 1 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. Title: Evaluation of astrophysically useful parameters for HD molecule Authors: Karthikeyan, B.; Rajamanickam, N.; Bagare, S. P. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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 Bibcode: 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 Bibcode: 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 2∑+ - X 2∑+, F 2∑+ - X 2∑+ systems of SrF and C 1∑+ - X 1∑+, G 1Π - X 1∑+ 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. Bibcode: 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 D1Δ,E1Π, F1Π and G1Σ+ A1Π 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. Bibcode: 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 1Σ+- X 1Σ+, C 1Σ+- X 1Σ+, c 3Σ+- b 3Σ+, f 3Π- b 3Σ+, F 1Π- B 1Σ+ and G1Σ+- B 1Σ+ 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. Bibcode: 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 E1Σ+, F1Σ+, /GΣ, HΠ, JΣ-X1Σ+ 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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 Rsun, 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 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. Bibcode: 1978JQSRT..19..455M Altcode: No abstract at ADS