IIA Institutional Repository

Browsing by Subject "White dwarfs"

Browsing by Subject "White dwarfs"

Sort by: Order: Results:

  • Are C60 Molecules Detectable in Circumstellar Shells of R Coronae Borealis Stars? 
    García-Hernández, D. A; Kameswara Rao, N; Lambert, D. L (IOP Publishing, 2011-03-10)
    The hydrogen-poor, helium-rich, and carbon-rich character of the gas around R Coronae Borealis (RCB) stars has been suggested to be a site for formation of C60 molecules. This suggestion is not supported by observations ...
  • Detection of a white dwarf companion to a blue straggler star in the outskirts of globular cluster NGC 5466 with the ultraviolet imaging telescope (UVIT) 
    Snehalata Sahu; Subramaniam, A; Simunovic, Mirko; Postma, J; Cote, Patrick; Kameswara Rao, N; Geller, Aaron M; Leigh, Nathan; Shara, Michael; Puzia, Thomas H; Stetson, Peter B (IOP Publishing, 2019-05-01)
    We report the discovery of a hot white dwarf (WD) companion to a blue straggler star (BSS) in the globular cluster (GC) NGC 5466, based on observations from the Ultra-Violet Imaging Telescope (UVIT) on board AstroSat. ...
  • Dust around R Coronae Borealis Stars. I. Spitzer/Infrared Spectrograph Observations 
    Aníbal García-Hernández, D; Kameswara Rao, N; Lambert, D. L (IOP Publishing, 2011-09-20)
    Spitzer/infrared spectrograph (IRS) spectra from 5 to 37 μm for a complete sample of 31 R Coronae Borealis stars (RCBs) are presented. These spectra are combined with optical and near-infrared photometry of each RCB at ...
  • Dust Around R Coronae Borealis Stars. II. Infrared Emission Features in an H-poor Environment 
    Garcia-Hernandez, D. A; Kameswara Rao, N; Lambert, D. L (IOP Publishing, 2013-08-20)
    Residual Spitzer/Infrared Spectrograph spectra for a sample of 31 R Coronae Borealis (RCB) stars are presented and discussed in terms of narrow emission features superimposed on the quasi-blackbody continuous infrared ...
  • Effects of modified gravity on microscopic properties and cooling timescale of white dwarfs 
    Wojnar, Aneta; Kalita, Surajit; Sarmah, Lupamudra (Elsevier B.V, 2024-03)
    There are currently two open questions in white dwarf physics: why are massive dwarfs observed less often in astronomical surveys, and why have not any super-Chandrasekhar white dwarfs been found despite the discovery of ...
  • Field blue straggler stars: discovery of white dwarf companions to blue metal-poor stars using UVIT/AstroSat 
    Panthi, Anju; Subramaniam, A; Vaidya, Kaushar; Jadhav, Vikrant V; Sharmila Rani; Sivarani, T; Pandey, Sindhu (Oxford University Press on behalf of Royal Astronomical Society, 2023-10)
    Blue metal-poor (BMP) stars are the main-sequence stars that appear bluer and more luminous than normal turn-off stars of metal-poor globular clusters. They are believed to be either field blue straggler stars (FBSS) formed ...
  • 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) – II. Evolutionary status of hot stars in M3 and M13 
    Kumar, Ranjan; Pradhan, Ananta C; Sahu, Snehalata; Subramaniam, A; Piridi, Sonika; Cassisi, Santi; Ojha, Devendra K (Oxford University Press on behalf of Royal Astronomical Society, 2023-06)
    We present a far-ultraviolet (FUV) study of hot stellar populations in the second parameter pair globular clusters (GCs) M3 and M13, as a part of the GC UVIT Legacy Survey programme (GlobULeS). We use observations made ...
  • GlobULeS – V. UVIT/AstroSat studies of stellar populations in NGC 362: detection of blue lurkers in a globular cluster 
    Dattatrey, Arvind K; Yadav, R. K. S; Kumawat, Gourav; Sharmila Rani; Singh, Gaurav; Subramaniam, A; Singh, Ravi S (Oxford University Press on behalf of Royal Astronomical Society, 2023-07)
    We report the discovery of four blue lurkers with low- and extremely low mass white dwarf (ELM WD) companions in the Galactic globular cluster NGC 362 using AstroSat’s Ultra Violet Imaging Telescope (UVIT). We analysed ...
  • The Nebular Remnant and Quiescent Spectrum of Nova Gk-Persei 
    Anupama, G. C; Prabhu, T. P (Royal Astronomical Society, 1993-07-15)
    CCD images of the nebular shell of the old nova GK Per in [N II] and [O III] emission lines, and also the quiescent spectrum in the optical region, are presented. Proper motion measurements of the knots in [N II]over the ...
  • Once in a blue moon: detection of bluing' during debris transits in the white dwarf WD 1145+017 
    Hallakoun, N; Xu, S; Maoz, D; Marsh, T. R; Ivanov, V. D; Dhillon, V. S; Bours, M. C. P; Parsons, S. G; Kerry, P; Sharma, S; Su, K; Sridharan, R|; Pravec, P; Kusnirak, P; Kucakova, H; Armstrong, J. D; Arnold, C (Oxford University Press on behalf of the Royal Astronomical Society, 2017-08)
    The first transiting planetesimal orbiting a white dwarf was recently detected in K2 data of WD 1145+017 and has been followed up intensively. The multiple, long and variable transits suggest the transiting objects are ...
  • Simulation of old open clusters for UVIT on ASTROSAT 
    Sindhu, N; Subramaniam, A; Anu Radha, C (IOP Publishing, 2015-10)
    The Ultra Violet Imaging Telescope (UVIT) is one of the payloads on the first Indian multiwavelength satellite ASTROSAT, which is expected to be launched by the Indian Space Research Organisation (ISRO) in the year 2015. ...
  • Type Ia Supernovae: Progenitors and Peculiarity 
    Nomoto, K; Tanaka, M; Kawabata, K. S; Sahu, D. K; Anupama, G. C (American Institute of Physics, 2007-08)
    Among the controversial issues on Type Ia supernovae (SNe Ia), we discuss (1) the evolutionary paths of the progenitor systems to SNe Ia, especially, the thermal stability of hydrogen shell burning in accreting white dwarfs, ...
  • UOCS –VIII. UV study of the open cluster NGC 2506 using ASTROSAT 
    Panthi, Anju; Vaidya, Kaushar; Jadhav, Vikrant V; Khushboo Rao, K; Subramaniam, A; Agarwal, Manan; Pandey, Sindhu (Oxford University Press on behalf of Royal Astronomical Society, 2022-11)
    We study an intermediate-age open cluster (OC) NGC 2506 using the ASTROSAT/UVIT data and other archival data. We identified 2175 cluster members using a machine learning-based algorithm, ML–MOC, on Gaia EDR3 data. Among ...
  • UVIT/AstroSat studies of blue straggler stars and post-mass transfer systems in star clusters: detection of one more blue lurker in M67 
    Subramaniam, A; Pnadey, Sindhu; Jadhav, Vikrant V; Snehalata Sahu (Indian Academy of Sciences, 2020-12)
    The blue straggler stars (BSSs) are main-sequence (MS) stars, which have evaded stellar evolution by acquiring mass while on the MS. The detection of extremely low mass (ELM) white dwarf (WD) companions to two BSSs and one ...

Search DSpace

Browse

My Account