Results 51 to 60 of about 276,909 (151)
Spectroscopic Properties of Cool Stars in the Sloan Digital Sky Survey: An Analysis of Magnetic Activity and a Search for Subdwarfs [PDF]
, 2004 We present a spectroscopic analysis of nearly 8000 late-type dwarfs in the Sloan Digital Sky Survey. Using the Hα emission line as an activity indicator, we investigate the fraction of active stars as a function of spectral type and find a peak near type
A. West +12 more
semanticscholar +1 more source
Why do hot subdwarf stars pulsate? [PDF]
Proceedings of the International Astronomical Union, 2015 AbstractHot subdwarf B stars (sdBs) are the stripped cores of red giants located at the bluest extension of the horizontal branch. Several different kinds of pulsators are found among those stars. The mechanism that drives those pulsations is well known and the theoretically predicted instability regions for both the short-period p-mode and the long ...
openaire +2 more sources
The magnetic fields of hot subdwarf stars [PDF]
Astronomy & Astrophysics, 2012 Detection of magnetic fields has been reported in several sdO and sdB stars. Recent literature has cast doubts on the reliability of most of these detections. We revisit data previously published in the literature, and we present new observations to clarify the question of how common magnetic fields are in subdwarf stars.
Landstreet, John D +4 more
openaire +2 more sources
Orbital periods of 22 subdwarf B stars [PDF]
Monthly Notices of the Royal Astronomical Society, 2003 Subdwarf B (sdB) stars are thought to be core helium burning stars with low mass hydrogen envelopes. In recent years it has become clear that many sdB stars lose their hydrogen through interaction with a binary companion and continue to reside in binary systems today.
L. Morales-Rueda +4 more
openaire +1 more source
Observational asteroseismology of hot subdwarf stars [PDF]
Astronomische Nachrichten, 2010 AbstractHot subdwarf stars are particularly challenging for asteroseismology due to their rapid pulsation periods, intrinsic faintness and relative rarity both in the field and in clusters. These features have ensured that the preferred method of observation up to now has been white‐light photometry, and all asteroseismological solutions to date have ...
openaire +2 more sources
NLTE wind models of hot subdwarf stars [PDF]
Astrophysics and Space Science, 2010 7 pages, to appear in Astrophysics and Space Science. The final publication will be available at springerlink.com.
Krticka, Jiri, Kubat, Jiri
openaire +2 more sources
, 2016 Hot subluminous stars of spectral type B and O are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage.
U. Heber
semanticscholar +1 more source
Astrophysical Journal Supplement SeriesWe conducted an analysis of the abundances of He, C, and N in 210 He-rich hot subdwarfs observed within both the Gaia Data Release 3 (DR3) and LAMOST DR7 data sets.
Yangping Luo +3 more
semanticscholar +1 more source
The Origins of Hot Subdwarf Stars [PDF]
Publications of the Astronomical Society of the Pacific, 1992 High signal-to-noise optical spectrophotometry of a sample of filed 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 ...
openaire +1 more source
Hot subdwarfs from the ESO Supernova Ia Progenitor Survey: II. Atmospheric parameters of subdwarf O stars [PDF]
, 2006 We address the origin and evolutionary status of hot subdwarf stars by studying the optical spectral properties of 58 subdwarf O (sdO) stars. Combining them with the results of our previously studied subdwarf B (sdB) stars, we aim at investigating ...
A. Stroeer +6 more
semanticscholar +1 more source