BORON ABUNDANCES ACROSS THE “Li–Be DIP” IN THE HYADES CLUSTER
- Institute for Astronomy, University of Hawai‘i at Manoa, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
- Department of Astronomy, Indiana University, 727 East 3rd Street, Swain Hall West 319, Bloomington, IN 47405-7105 (United States)
- Department of Physics and Astronomy, Clemson University, 118 Kinard Laboratory of Physics, Clemson, SC 29634-0978 (United States)
- Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard and Tripicco. Boesgaard and 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 Å. The light elements Li, Be, and B are destroyed inside stars at increasingly hotter temperatures: 2.5, 3.5, and 5 × 10{sup 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.
- OSTI ID:
- 22667349
- Journal Information:
- Astrophysical Journal, Vol. 830, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Beryllium abundances in the lithium-deficient Hyades F stars
On the Iron Abundance Anomaly in K-dwarf and Hyades Stars