期刊
ASTROPHYSICAL JOURNAL
卷 830, 期 1, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.3847/0004-637X/830/1/49
关键词
open clusters and associations: general; open clusters and associations: individual (Hyades); stars: abundances; stars: evolution; stars: late-type; stars: solar-type
资金
- NSF grants [AST-00-97955, AST-05-05899]
- [HST-GO-09886]
- [HST-GO-12294]
- Direct For Mathematical & Physical Scien
- Division Of Astronomical Sciences [1211699] Funding Source: National Science Foundation
Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard & Tripicco. Boesgaard & King discovered corresponding, but smaller, deficiencies in Be in the same narrow temperature region in the Hyades. Using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we investigate B abundances in the Hyades F stars to look for a potential B dip using the B I resonance line at 2496.8 angstrom. The light elements Li, Be, and B are destroyed inside stars at increasingly hotter temperatures: 2.5, 3.5, and 5. x. 10(6) K, respectively. Consequently, these elements survive to increasingly greater depths in a star and their surface abundances indicate the depth and thoroughness of mixing in the star. We have (re) determined Li abundances/upper limits for 79 Hyades dwarfs, Be for 43 stars, and B for 5 stars. We find evidence for a small drop in the B abundance across the Li-Be dip. The B abundances for the four stars in the temperature range 6100-6730 K fit the B-Be correlation found previously by Boesgaard et al. Models of rotational mixing produce good agreement with the relative depletions of Be and B in the dip region. We have compared our nLTE B abundances for the three high B stars on either side of the Li-Be dip with those found by Duncan et al. for the two Hyades giants. This confirms the factor of 10 decline in the B abundance in the Hyades giants as predicted by dilution due to the deepening of the surface convection zone.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据