Astronomy and Astrophysics – Astronomy
Scientific paper
Jul 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005aspc..334..297u&link_type=abstract
14th European Workshop on White Dwarfs, ASP Conference Series, Vol. 334 Proceedings of a meeting held at Kiel, July 19-23, 2004
Astronomy and Astrophysics
Astronomy
7
Scientific paper
For the example Teff = 35000 K, log g = 6.0 the effect of diffusion and weak winds on the chemical composition of helium- and carbon-enriched subdwarf B stars is investigated with an initial composition as predicted by Cassisi et al. (2003) for the helium flash induced mixing in Population II stars. The elements H, He, C, N and O are taken into account simultaneously in the calculations for time scales of 108 yr. From theoretical considerations mass loss rates in the range 10-14 M&sun;/yr ≤ dot M ≤ 10-12 M&sun; /yr are plausible for the given stellar parameters. With an initial number ratio H/He = 1.7 \cdot 10-3 the upward diffusion of hydrogen leads to an increase of the H/He ratio between a factor of ten for dot M = 10-12 M&sun;/yr and a factor of about 200 to H/He ≈ 0.4 for dot M = 10-14 M&sun;/yr. For an initial ratio of H/He larger by a factor of ten, the upward diffusion of hydrogen could explain the H/He ratios in "blue hook" stars of globular clusters analyzed by Moehler et al. (2004).
No associations
LandOfFree
The Upward Diffusion of Hydrogen in Helium-Rich Subdwarf B Stars 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 The Upward Diffusion of Hydrogen in Helium-Rich Subdwarf B Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Upward Diffusion of Hydrogen in Helium-Rich Subdwarf B Stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1434385