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Browsing by Author "Pandey, G"

Browsing by Author "Pandey, G"

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  • Early time optical spectroscopy of supernova SN 1998S 
    Anupama, G. C; Sivarani, T; Pandey, G (EDP Sciences, 2001-02)
    We present medium-resolution optical spectra of the type II supernova SN 1998S obtained during the pre-maximum, maximum and early decline phases. The early decline spectra show complex Balmer line profiles: a narrow P-Cygni ...
  • The emission-line spectrum of the hot R Coronae Borealis star MV SGR 
    Pandey, G; Kameswara Rao, N; Lambert, D. L (Royal Astronomical Society, 1996-10)
    Spectra of MV Sgr obtained at CTIO in 1992 May show many emission lines in the red. Most of the emission lines show two components with a minimum centred at the stellar velocity. Species represented include H, HeI, TiII ...
  • Fluorine detection in hot extreme helium stars 
    Bhowmick, A; Pandey, G; Lambert, D. L (Springer, 2020-12)
    The origin and evolution of hydrogen-deficient stars are not yet adequately understood. Their chemical peculiarities, along with hydrogen-deficiency, makes them stand out from the rest and sheds light on their possible ...
  • Fluorine in R Coronae Borealis Stars 
    Pandey, G; Lambert, D. L; Kameswara Rao, N (Astronomical Society of the Pacific, 2008)
    Neutral fluorine lines are identified in the optical spectra of several R Coronae Borealis stars (RCBs) at maximum light. These lines provide the first measurement of the fluorine abundance in these stars. Fluorine is ...
  • Fluorine in R Coronae Borealis Stars 
    Pandey, G; Lambert, D. L; Kameswara Rao, N (University of Chicago Press, 2008-02)
    Neutral fluorine (F i) lines are identified in the optical spectra of several R Coronae Borealis stars (RCBs) at maximum light. These lines provide the first measurement of the fluorine abundance in these stars. Fluorine ...
  • The galactic R coronae borealis stars and the final he-shell flash object V4334Sgr (Sakurai’s object): a comparison 
    Hema, B. P; Pandey, G; Lambert, D. L (Proceedings of Science, 2012-08)
    The high resolution optical spectra of H-deficient stars, R Coronae Borealis stars and H-deficient carbon stars are analyzed by synthesizing the C2 Swan bands (0,1), (0,0), and (1,0) using our detailed line-list and ...
  • The Galactic R Coronae Borealis Stars: The C2 Swan Bands, the Carbon Problem, and the 12C/13C Ratio 
    Hema, B. P; Pandey, G; Lambert, D. L (IOP Publishing, 2012-03-10)
    Observed spectra of R Coronae Borealis (RCB) and hydrogen-deficient carbon (HdC) stars are analyzed by synthesizing the C2 Swan bands (1, 0), (0, 0), and (0, 1) using our detailed line list and the Uppsala model atmospheres. ...
  • Globular Cluster UVIT Legacy Survey (GlobULeS) – I. FUV–optical colour–magnitude diagrams for eight globular clusters 
    Sahu, Snehalata; Subramaniam, A; Singh, Gaurav; Yadav, Ramakant; Valcarce, Aldo R; Choudhury, Samyaday; Sharmila Rani; Deepthi, S. Prabhu; Chung, Chul; Cote, Patrick; Leigh, Nathan; Geller, Aaron M; Chatterjee, Sourav; Kameswara Rao, N; Bandyopadhyay, Avrajit; Shara, Michael; Dalessandro, Emanuele; Pandey, G; Postma, Joesph E; Hutchings, John; Simunovic, Mirko; Stetson, Peter B; Sivarani, T; Puzia, Thomas; Sohn, Young-Jong (Oxford University Press on behalf of the Royal Astronomical Society, 2022-07)
    We present the first results of eight globular clusters (GCs) from the AstroSat/UVIT Legacy Survey programme GlobULeS based on the observations carried out in two far-ultraviolet (FUV) filters (F148W and F169M). The ...
  • Globular Cluster UVIT Legacy Survey (GlobULeS). III. Omega Centauri in Far-ultraviolet 
    Deepthi, S. Prabhu; Subramaniam, A; Sahu, Snehalata; Chung, Chul; Leigh, Nathan W. C; Dalessandro, Emanuele; Chatterjee, Sourav; Kameswara Rao, N; Shara, Michael; Cote, Patrick; Choudhury, Samyaday; Pandey, G; Valcarce, Aldo A. R; Singh, G; Postma, Joesph E; Sharmila Rani; Bandyopadhyay, Avrajit; Geller, Aaron M; Hutchings, John; Puzia, Thomas; Simunovic, Mirko; Sohn, Young-Jong; Sivarani, T; Yadav, Ramakant Singh (American Astronomical Society, 2022-11-10)
    We present the first comprehensive study of the most massive globular cluster, Omega Centauri, in the farultraviolet (FUV), extending from the center to ∼28% of the tidal radius using the Ultraviolet Imaging Telescope on ...
  • Helium Enhancement in the Metal-rich Red Giants of ω Centauri 
    Hema, B. P; Pandey, G; Kurucz, R. L; Prieto, C. A (IOP Publishing, 2020-07-01)
    The helium-enriched (He-enriched) metal-rich red giants of ω Centauri, discovered by Hema & Pandey using the low-resolution spectra from the Vainu Bappu Telescope, and confirmed by the analyses of the high-resolution spectra ...
  • High-resolution Infrared Spectrograph for Exoplanet Characterization with the Keck and Thirty Meter Telescopes 
    Mawet, Dimitri; Fitzgerald, Michael; Konopacky, Quinn; Beichman, Charles; Jovanovic, Nemanja; Dekany, Richard; Hover, David; Chisholm, Eric; Ciardi, David; Artigau, Etienne; Banyal, Ravinder; Beatty, Thomas; Benneke, Bjorn; Blake, Geoffrey A; Burgasser, Adam; Canalizo, Gabriela; Chen, Guo; Do, Tuan; Doppmann, Greg; Doyon, Rene; Dressing, Courtney; Fang, Min; Greene, Thomas; Hillenbrand, Lynne; Howard, Andrew; Kane, Stephen; Kataria, Tiffany; Kempton, Eliza; Knutson, Heather; Kotani, Takayuki; Lafreniere, David; Liu, Chao; Nishiyama, Shogo; Pandey, G; Plavchan, Peter; Prato, Lisa; Rajaguru, S. P; Robertson, Paul; Salyk, Colette; Sato, Bun’ei; Schlawin, Everett; Sengupta, S; Sivarani, T; Skidmore, Warren; Tamura, Motohide; Terada, Hiroshi; Vasisht, Gautam; Wang, Ji; Zhang, Hui (American Astronomical Society, 2019-09)
    HISPEC (High-resolution Infrared Spectrograph for Exoplanet Characterization) is a proposed diffractionlimited spectrograph for the W.M. Keck Observatory, and a pathfinder for the MODHIS facility project (Multi-Object ...
  • High-resolution spectroscopy of the relatively hydrogen-poor metal-rich giants in the globular cluster ω centauri 
    Hema, B. P; Pandey, G; Srianand, R (IOP Publishing, 2018-09)
    High-resolution optical spectra are analyzed for two of the four metal-rich, mildly hydrogen-poor or helium-enhanced giants discovered by Hema & Pandey, along with their comparison normal (hydrogen-rich) giants. The strengths ...
  • The horizontal branch morphology of the globular cluster NGC 1261 using AstroSat 
    Sharmila Rani; Pandey, G; Subramaniam, A; Sahu, S; Kameswara Rao, N (Indian Academy of Sciences, 2020-12)
    We present the results obtained from the UV photometry of the globular cluster NGC 1261 using far-UV (FUV) and near-UV (NUV) images acquired with the Ultraviolet Imaging Telescope (UVIT) on-board the AstroSat satellite. ...
  • The hot γ Doradus and Maia stars 
    Balona, L. A; Engelbrecht, C. A; Joshi, Y. C; Joshi, S; Sharma, K; Semenko, E; Pandey, G; Chakradhari, N. K; Mkrtichian, D; Hema, B. P; Nemec, J. M (Oxford University Press on behalf of the Royal Astronomical Society, 2016-09)
    The hot γ Doradus stars have multiple low frequencies characteristic of γ Dor or SPB variables, but are located between the red edge of the SPB and the blue edge of the γ Dor instability strips where all low-frequency ...
  • Infrared Space Observatory Spectra of R Coronae Borealis Stars. I. Emission Features in the Interval 3-25 Microns 
    Lambert, D. L; Kameswara Rao, N; Pandey, G; Ivans, I. I (American Astronomical Society, 2001-07)
    Infrared Space Observatory 3-25 μm spectra of the R Coronae Borealis stars V854 Cen, R CrB, and RY Sgr are presented and discussed. Sharp emission features coincident in wavelength with the well-known unidentified emission ...
  • Interstellar dust studies with TAUVEX 
    Maheswar, G; Muthu, C; Sujatha, N. V; Pandey, G; Bhatt, H. C; Kameswara Rao, N; Murthy, J (Astronomical Society of India, 2007-06)
    We propose to carry out studies on the properties of inter- stellar dust using TAUVEX. Through the multi-band TAUVEX observations, particularly with the use of filters optimized for extinction observations of the 2175 ° ...
  • Investigation of the helium enhancement in a super lithium-rich giant HD 77361 
    Hema, B. P; Pandey, G (Indian Academy of Sciences, 2020-12)
    In this work, the helium-enhancement (He-enhancement) in the lithium-rich (Li-rich) K-giant HD 77361 is investigated using the strengths of the MgH band and the Mg I lines. The detailed abundance analysis and also the ...
  • Investigations of Hydrogen Deficient Stars and Related Objects 
    Pandey, G (Indian Institute of Astrophysics, Bangalore, 1999-09)
  • Is the Post-AGB Star SAO 40039 Mildly Hydrogen-Deficient? 
    Sumangala Rao, S; Pandey, G; Lambert, D. L; Giridhar, S (IOP Publishing, 2011-08-10)
    We have conducted an LTE abundance analysis for SAO 40039, a warm post-AGB star whose spectrum is known to show surprisingly strong He I lines for its effective temperature and has been suspected of being H-deficient and ...
  • Neon and CNO Abundances for Extreme Helium Stars—A Non-LTE Analysis 
    Pandey, G; Lambert, D. L (IOP Publishing, 2011-02)
    A non-LTE (NLTE) abundance analysis was carried out for three extreme helium stars (EHes): BD+10° 2179, BD–9° 4395, and LS IV+6° 002, from their optical spectra with NLTE model atmospheres. NLTE TLUSTY model atmospheres ...

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