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Browsing by Subject "Stars: Abundances"

Browsing by Subject "Stars: Abundances"

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  • Abundance Analyses of Field RV Tauri Variables. III. DY Aquilae, SS Geminorum, CT Orionis, and CE Virginis 
    Gonzalez, G; Lambert, D. L; Giridhar, S (The American Astronomical Society, 1997-05)
    Analyses of the photospheric compositions of the four field RV Tauri stars, DY Aql, SS Gem, CT Ori, and CE Vir, indicate that to varying degrees they have experienced fractionation processes that have preferentially depleted ...
  • Abundance Analyses of the Field RV Tauri Variables: EP Lyrae, DY Orionis, AR Puppis, and R Sagittae 
    Gonzalez, G; Lambert, D. L; Giridhar, S (The American Astronomical Society, 1997-04)
    Analyses of the photospheric compositions of the four field RV Tauri stars, EP Lyr, DY Ori, AR Pup, and R Sge, indicate that to varying degrees they have experienced fractionation processes that have preferentially depleted ...
  • Abundance evolution of intermediate mass elements (C to Zn) in the Milky Way halo and disk 
    Goswami, A; Prantzos, N (European Southern Observatory, 2000-07)
    We present a comprehensive study of the evolution of the abundances of intermediate mass elements, from C to Zn, in the Milky Way halo and in the local disk. We use a consistent model to describe the evolution of those two ...
  • Abundance similarities between the RCrB star V854Cen and the born-again Sakurai's object 
    Asplund, M; Gustafsson, B; Kameswara Rao, N; Lambert, D. L (European Southern Observatory, 1998-04)
    The elemental abundances of the mildly hydrogen-deficient R Coronae Borealis (RCrB) star V854Cen have been estimated. The RCrB stars have been divided into majority and minority classes judging by their abundance patterns. ...
  • Abundances of the Sup/3 He star 3 CEN A (B5 IIIp) from ultraviolet IUE spectra 
    Castelli, F; Parthasarathy, M; Hack, M (European Southern Observatory, 1997-05)
    High resolution (0.010-0.025nm) IUE ultraviolet spectra of the peculiar Sup/3He star 3 Cen A were analyzed in the whole 120-320nm region. Abundances were derived from the comparison of the observed and computed spectra. ...
  • Chemical analysis of CH stars – II. Atmospheric parameters and elemental abundances 
    Drisya, K; Goswami, A (Oxford University Press on behalf of the Royal Astronomical Society, 2015-01-21)
    We present detailed chemical analyses for a sample of 12 stars selected from the CH star catalogue of Bartkevicius. The sample includes two confirmed binaries, four objects that are known to show radial velocity variations ...
  • Chemical analysis of three barium stars: HD 51959, HD 88035, HD 121447 
    Drisya, K; Goswami, A; Sridhar, N; Masseron, T; Meenakshi, P (Oxford University Press on behalf of the Royal Astronomical Society, 2018-05)
    We present elemental abundance results from high-resolution spectral analysis of three nitrogen-enhanced barium stars. The analysis is based on spectra obtained with the fibre- fed extended range optical spectrograph ...
  • Chemical composition and evolutionary status of nine UV-bright stars in five globular clusters from VLT/UVES spectra 
    Jasniewicz, G; de Laverny, P; Parthasarathy, M; Lèbre, A; Thévenin, F (EDP Sciences, 2004-08)
    We have derived the chemical composition of nine UV-bright stars belonging to five Galactic globular clusters of various metallicities ([Fe/H] from -1.0 to -2.4 dex). The analyses are based on high resolution spectra ...
  • Chemical composition of evolved stars of high galactic latitude 
    Giridhar, S; Arellano Ferro, A (EDP Sciences, 2005-11)
    We have carried out abundance analysis for a sample of high galactic latitude supergiants in search of evolved stars. We find that HD 27381 has atmospheric parameters and an abundance pattern very similar to that of the ...
  • Chemical composition of HD 179821 (IRAS 19114+0002) 
    Thévenin, F; Parthasarathy, M; Jasniewicz, G (European Southern Observatory, 2000-07)
    A LTE analysis of medium resolution spectra of HD 179821 has been made. Derived atmospheric parameters of HD 179821 are K, and [Fe/H]=-0.5. The position of the star in the H-R diagram, its high radial velocity (Vr=100 ...
  • The chemical composition of IRAS 05341+0852: a post-AGB F supergiant with 21 MU M emission 
    Reddy, B. E; Parthasarathy, M; Gonzalez, G; Bakker, E. J (European Southern Observatory, 1997-12)
    An abundance analysis of the photosphere of the F-type Post-AGB candidate IRAS 05341+0852 is presented. The analysis of the spectra suggests that the atmospheric model: Teff=6500 K, log g=0.5, xi_ {t}=5 km s(-1) and ...
  • Chemical Compositions of Four Metal-poor Giant Stars 
    Giridhar, S; Lambert, D. L; Gonzalez, G; Pandey, G (University of Chicago Press, 2001-05)
    We present the chemical compositions of four K giants (CS 22877-1, CS 22166-16, CS 22169-35, and BS 16085-0050) that have [Fe/H] in the range -2.4 to -3.1. Metal-poor stars with [Fe/H]<-2.5 are known to exhibit considerable ...
  • The Chemical Compositions of the SRD Variable Stars. III. KK Aquilae, AG Aurigae, Z Aurigae, W Leo Minoris, and WW Tauri 
    Giridhar, S; Lambert, D. L; Gonzalez, G (The Astronomical Society of the Pacific, 2000-12)
    Chemical compositions are derived from high-resolution spectra for five field SRd variables. These supergiants not previously analyzed are shown to be metal poor: KK Aql with [Fe/H]=-1.2, AG Aur with [Fe/H]=-1.8, Z Aur ...
  • Detection of Zinc in the Very Metal-Poor Post-AGB Star HR 4049 
    Takeda, Yoichi; Parthasarathy, M; Aoki, W; Ita, Yoshifusa; Nakada, Yoshikazu; Izumiura, Hideyuki; Noguchi, Kunio; Takada-Hidai, Masahide; Sato, B; Tajitsu, Akito; Honda, Satoshi; Kawanomoto, Satoshi; Ando, Hiroyasu; Karoji, Hiroshi (Astronomical Society of Japan, 2002-10-25)
    We report on the detection of two Zn I lines at 4722.15Å and 4810.53Å in the high-quality spectrum of the very metal-poor post-AGB star HR 4049, which was obtained with the High Dispersion Spectrograph attached to the ...
  • Elemental Abundances and Atmospheric Parameters of Seven F-G Supergiants 
    Giridhar, S; Ferro, A; Parrao, L (Astronomical Society of the Pacific, 1997-10)
    Spectroscopic abundance determinations for a sample of seven F-G stars have been carried out. The majority of them have large galactic latitudes. One objective in deriving spectroscopic abundances is to differentiate evolved ...
  • FG Sagittae: A Newborn R Coronae Borealis Star? 
    Gonzalez, G; Lambert, D. L; Wallerstein, G; Kameswara Rao, N; Smith, V. V; McCarthy, J. K (The American Astronomical Society, 1998-01)
    We have monitored FG Sge's spectroscopic changes since the time just prior to its dramatic fading in 1992 August. The most significant qualitative changes in the spectrum include large variations in the strength of the C2 ...
  • HD 77361: a new case of super Li-rich K giant with anomalous low C-12/C-13 ratio 
    Bharat Kumar, Y; Reddy, B. E (The American Astronomical Society, 2009-09)
    Results from high-resolution spectroscopic analysis of HD77361 are reported. LTE analysis shows that HD77361 is a K giant of atmospheric parameters: T-eff = 4580 +/- 75 K, log g = 2.5 +/- 0.1, and xi(t) = 1.40 +/- 0.5 km ...
  • HD209621: abundances of neutron-capture elements 
    Goswami, A; Aoki, W (Blackwell Publishing, 2010-05)
    High-resolution spectra obtained from the Subaru Telescope High Dispersion Spectrograph have been used to update the stellar atmospheric parameters and metallicity of the star HD 209621. We have derived a metallicity of ...
  • High resolution spectroscopy of the high latitude rapidly evolving post-AGB star SAO 85766 (= IRAS 18062+2410) 
    Parthasarathy, M; García-Lario, P; Sivarani, T; Manchado, A; Sanz Fernández de Córdoba, L (European Southern Observatory, 2000-05)
    SAO 85766 (b = +20o) is an IRAS source with far-infrared colours similar to planetary nebulae. According to the HDE catalogue, its spectrum in 1940 was that of an A5 star. The UV fluxes and colours derived from data obtained ...
  • Moving groups in the galactic disc 
    Ramya, P; Reddy, B. E (Cambridge University Press, 2014-01)
    We present results of chemical abundance study of a few representative stellar streams of Galactic thick and thin discs. Arcturus stream, which was proposed to have an extragalactic origin, and a recently detected stream ...

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