Abundance analyses of three helium-rich sdB stars

Autor:	Timur Şahin, C. S. Jeffery, A. Ahmad, N. T. Behara, N. Naslim
Rok vydání:	2010
Předmět:	Physics White dwarf Astronomy chemistry.chemical_element Astronomy and Astrophysics Astrophysics Subdwarf Cosmology Spectral line Stars chemistry Space and Planetary Science Abundance (ecology) Helium
Zdroj:	Astrophysics and Space Science. 329:119-125
ISSN:	1572-946X 0004-640X
DOI:	10.1007/s10509-010-0334-x
Popis:	As part of an extended study of the surface abundances of extremely helium-rich hot subdwarfs, high-resolution optical echelle spectra of the three helium-rich subdwarf B stars LB 1766, SB 21 and BPS 22940–0009 are presented. Opacity-sampled line-blanketed model atmospheres have been used to derive atmospheric properties and surface abundances. All three stars are moderately metal-poor compared with the Sun ([Fe/H]≈−0.4). The first two stars are nitrogen-rich He-sdBs, while the third is a carbon-rich He-sdB. The surface composition and locus of single N-rich He-sdBs are currently best explained by the merger of two helium white dwarfs. C-rich He-sdBs require further investigation.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8e3c80025fc092d31c58dea1b88d42d6 https://doi.org/10.1007/s10509-010-0334-x Zobrazit plný text záznamu Plný text ve formátu PDF