Abundances in the Hot DZ Star CBS 127: How Efficient Is Hydrogen Screening?
Abstract
A revised and updated grid of cool helium-rich model atmospheres which includes the effect of varying hydrogen abundance is used to analyze the temperature and abundance of the DZ white dwarf CBS 127. Comparisons of the star to several other DZ white dwarfs with similar T(e)s show that CBS 137 is the hottest DZ star and lies near the boundary temperature above which it has been proposed that hydrogen accretion may be prevented. Based on the results, a specifically defined single lower boundary temperature for screening is rejected, and it is demonstrated that the propeller must operate over a very broad range of T(eff), down to T(eff) as low as 5800 K, with highly variable efficiency.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1990
- DOI:
- 10.1086/169306
- Bibcode:
- 1990ApJ...362..691S
- Keywords:
-
- Hot Stars;
- Reference Atmospheres;
- Stellar Atmospheres;
- Stellar Temperature;
- White Dwarf Stars;
- Abundance;
- Accretion Disks;
- Hydrogen;
- Temperature Distribution;
- Astrophysics;
- STARS: ABUNDANCES;
- STARS: ACCRETION;
- STARS: WHITE DWARFS