Physical parameters for subdwarf B stars with composite spectra
نویسندگان
چکیده
منابع مشابه
Mass loss predictions for Subdwarf B stars
We present the results of Monte Carlo mass-loss computations for hot low-mass stars, specifically for Subdwarf B (SdB) stars. It is shown that the massloss rates on the Horizontal Branch (HB) computed from radiative line-driven wind models are not high enough to create SdB stars. We argue, however, that mass loss plays a role in the chemical abundance patterns observed both in field SdB stars, ...
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We describe a method for computing theoretical photometric amplitude ratios for a number of modes of nonradially pulsating subdwarf B stars in both SDSS and UBVR systems. In order to avoid costly solutions of the non-adiabatic nonradial pulsation equations, we have adopted the adiabatic approximation. We argue that this is a valid approach, at least for the V361 Hya stars, because observations ...
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Subdwarf B (sdB) stars (and related sdO/sdOB stars) are believed to be helium coreburning objects with very thin hydrogen-rich envelopes. In recent years it has become increasingly clear from observational surveys that a large fraction of these objects are members of binary systems. To better understand their formation, we here present the results of a detailed investigation of the three main b...
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Intermediate dispersion spectroscopy of a sample of 40 hot subdwarf B stars between 5500 A and 9000 A has been obtained. The sample includes a large fraction of targets which have been studied photometrically. Seven targets show strong lines due to the infrared Ca ii triplet, the unequivocal signature of a cool companion. The positive Ca ii identiications include known photometric binaries and ...
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Context. Diffusion of atoms can be important during quiescent phases of stellar evolution. Particularly in the very thin inert envelopes of subdwarf B stars, diffusive movements will considerably change the envelope structure and the surface abundances on a short timescale. Also, the subdwarfs will inherit the effects of diffusion in their direct progenitors, namely giants near the tip of the r...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2002
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20020099