Metal abundances of subdwarf B stars—the extended sample

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

5

Stars: Horizontal Branch, Stars: Abundances, Stars: Chemically Peculiar, Stars: Atmospheres

Scientific paper

The formation of sdBs as well as the chemical composition of their atmospheres is still puzzling. While helium and other light elements are depleted relative to solar values, heavy elements are highly enriched. Diffusion processes in the hot, radiative atmosphere of these stars are the most likely explanation. Although several attempts have been made, it has not yet been possible to model all the observed features of sdB atmospheres. A drawback of most prior studies was the small sample size. We present a detailed abundance analysis of 139 sdBs. A general trend of enrichment was found with increasing temperature for most of the heavier elements. The lighter elements like carbon, oxygen and nitrogen are depleted and less affected by temperature. Although there is considerable scatter from one star to the other, the general abundance patterns in most sdBs are similar. An interplay between gravitational settling, radiative levitation and weak winds is most likely responsible. About 3% of the analysed stars show an enrichment in carbon and helium, which cannot be explained in the framework of diffusion alone. Nuclear processed material must have been transported to the surface somehow.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Metal abundances of subdwarf B stars—the extended sample does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Metal abundances of subdwarf B stars—the extended sample, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Metal abundances of subdwarf B stars—the extended sample will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1404075

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.