Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-09-26
Astronomy and Astrophysics
Astrophysics
10 pages, 5 eps-files, accepted for publication in Astronomy and Astrophysics
Scientific paper
10.1051/0004-6361:20011334
We present the result of differential spectral analyses of a further four apparently normal B-type stars. Abundance anomalies (e.g. He, C, N enrichment), slow rotation and/or high gravities suggest that the programme stars are evolved low-mass B-type stars. In order to trace their evolutionary status several scenarios are discussed. Post-AGB evolution can be ruled out. PG 0229+064 and PG 1400+389 could be horizontal branch (HB) stars, while HD 76431 and SB 939 have already evolved away from the extreme HB (EHB). The low helium abundance of HD 76431 is consistent with post-EHB evolution. The enrichment in helium, carbon and nitrogen of the remaining stars can be explained either by deep mixing of nuclearly processed material to the surface or by diffusion processes modified by magnetic fields and/or stellar winds. A kinematic study of their galactic orbits indicates that the stars belong to an old disk population.
Edelmann Heinz
Heber Uli
Ramspeck M.
No associations
LandOfFree
Early type stars at high galactic latitudes II. Four evolved B-type stars of unusual chemical composition 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 Early type stars at high galactic latitudes II. Four evolved B-type stars of unusual chemical composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Early type stars at high galactic latitudes II. Four evolved B-type stars of unusual chemical composition will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-634900