Results 141 to 150 of about 1,072 (156)

NLTE Analysis of Extremely Helium Rich Subdwarf O-Stars

1993
The NLTE analyses of four extremely helium rich sdO stars are presented. Effective temperatures, gravities and the abundances of H, He, C, N, O, Ne, Mg and Si have been determined. It is found that three of the programme stars have very similar parameters. The positions of these stars in the (T eff,log g) diagram indicate, that they are post-EHB stars.
openaire   +1 more source

A spectroscopic and photometric investigation of the extreme helium-rich star HD 168476

1979
Spectra were obtained from several sources for a fine abundance analysis of the extreme helium-rich star HD 168476. The atmospheric parameters are found using theoretical models and abundances determined for the ions identified in the spectra.
openaire   +2 more sources

Pulsation Stability of Helium-Rich Subdwarf B Stars

Astrophysics and Space Science, 2004
J -E Solheim, C S Jeffery, R Østensen
exaly  

NLTE Spectral Analysis of the Intermediate Helium-Rich Subdwarf B Star CPD−20°1123

Monthly Notices of the Royal Astronomical Society, 2020
Lisa Löbling
exaly  

Abundance Analyses of Three Helium-Rich sdB Stars

Astrophysics and Space Science, 2010
Timur Şahin, C S Jeffery
exaly  

Population Synthesis of Helium White Dwarf–Red Giant Star Mergers and the Formation of Lithium-Rich Giants and Carbon Stars

Astrophysical Journal, 2020
Xianfei Zhang, Shaolan Bi, C Simon Jeffery   +2 more
exaly  

New Helium Spectrum Variable and a New Helium-Rich Star.

Publications of the Astronomical Society of the Pacific, 1975
N R Walborn
exaly  

Outbursts of Luminous Blue Variable Stars From Variations in the Helium Opacity

Nature, 2018
Lars Bildsten, Eliot Quataert, Yan-Fei Jiang   +2 more
exaly  

Discovery of Pulsation in a Helium-Rich Subdwarf B Star

Astronomy and Astrophysics, 2005
C S Jeffery
exaly  

Physical Parameters of Helium-Rich Subdwarf B Stars From Medium Resolution Optical Spectroscopy

Astronomy and Astrophysics, 2003
C S Jeffery
exaly