Sign on

SAO/NASA ADS Astronomy Abstract Service


· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (337) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (68)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Atmospheric parameters of field subdwarf B stars
Authors:
Saffer, Rex A.; Bergeron, P.; Koester, D.; Liebert, James
Affiliation:
AA(Space Telescope Science Inst., Baltimore, MD, US), AB(Space Telescope Science Inst., Baltimore, MD, US), AC(Inst. für Theoretische Physik und Sternwarte, Kiel, Germany), AD(Inst. für Theoretische Physik und Sternwarte, Kiel, Germany)
Publication:
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 432, no. 1, p. 351-366 (ApJ Homepage)
Publication Date:
09/1994
Category:
Astronomy
Origin:
STI
NASA/STI Keywords:
Abundance, B Stars, Horizontal Branch Stars, Stellar Atmospheres, Stellar Gravitation, Stellar Temperature, Subdwarf Stars, Absorption Spectra, Color-Magnitude Diagram, Helium, Hertzsprung-Russell Diagram, Hydrogen, Line Spectra, Photosphere, Stellar Spectrophotometry, Ultraviolet Spectra, White Dwarf Stars
DOI:
10.1086/174573
Bibliographic Code:
1994ApJ...432..351S

Abstract

High signal-to-noise ratio optical spectrophotometry of a sample of field subluminous B stars drawn largely from the Palomar Green ultraviolet-excess survey is analyzed with a new grid of model atmospheres and synthetic spectra. The stellar effective temperatures, surface gravities, and photospheric helium abundances are determined simultaneously from a detailed analysis of hydrogen and helium absorption line profiles. The derived temperatures and gravities place the subluminous B stars in the theoroetical Hertzsprung-Russell (H-R) diagram along and bounded below by theoretical sequences of the zero-age extended horizontal branch, lending strong support to the hypothesis that these stars are composed of helium-burning cores of approximately 0.5 solar mass overlain by very thin layers of hydrogen (approximately less than 0.02 solar mass). Various scenarios for their past evolutionary history are examined in the context of their probable future evolution into white dwarfs of lower than average mass.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences



More Article Retrieval Options

HELP for Article Retrieval


Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)


Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints