Beryllium Abundances in F and G Dwarfs in the Coma Cluster and the Ursa Major Moving Group from Keck HIRES Observations

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

12

Galaxy: Open Clusters And Associations: Individual: Name: Coma, Galaxy: Open Clusters And Associations: Individual: Name: Ursa Major Group, Stars: Abundances, Stars: Rotation

Scientific paper

The study of both light elements Li and Be in open clusters of known properties can reveal the internal structure and the mechanisms of mixing in main-sequence stars as a function of age and composition. In previous work, we have investigated the older Hyades cluster and the younger Pleiades and α Per clusters. The Coma Berenices cluster and the UMa moving group are intermediate in age between the Hyades and Pleiades and provide a good linchpin for the influence of stellar age on light-element abundances; there are dips in the mid-F stars in both Li and Be in the Hyades but no Be dip and only a minor Li dip in the Pleiades. We have made observations of the resonance doublet of Be II near 3130 Å in 13 Coma and six UMa stars with the Keck I telescope and the High Resolution Echelle Spectrometer. The Be abundances were determined by spectrum synthesis. In the F dwarfs in Coma, there are both Li and Be deficiencies, indicating that the depletions occur during the main-sequence phase of evolution but do not become evident until an age of 200-300 Myr. For both UMa and Coma stars, the Li depletion is greater than the Be depletion at all temperatures, but there is little, if any, Be depletion in stars with Teff<6000 K. In the four clusters studied for Be, the mean Be abundance for stars with temperatures less than 6000 K is logN(Be/H)+12.00=1.27, independent of age or metal content. For the hotter stars (5850-6680 K), the Li and Be abundances are correlated, indicating that the depletion probably occurs simultaneously; this matches the results for the field stars and the Hyades and the predictions of Li and Be depletion by rotationally induced mixing.

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

Beryllium Abundances in F and G Dwarfs in the Coma Cluster and the Ursa Major Moving Group from Keck HIRES Observations 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 Beryllium Abundances in F and G Dwarfs in the Coma Cluster and the Ursa Major Moving Group from Keck HIRES Observations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Beryllium Abundances in F and G Dwarfs in the Coma Cluster and the Ursa Major Moving Group from Keck HIRES Observations will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-919841

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