Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-01-20
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
Accepted by ApJ; 21 pages, 5 figures
Scientific paper
Despite the extensive study of lithium depletion during pre-main-sequence contraction, studies of individual stars show discrepancies between ages determined from the HR diagram and ages determined from lithium depletion (Song et al. 2002, White & Hillenbrand 2005) indicating open questions in the pre-main-sequence evolutionary models. To further test these models, we present high resolution spectra for members of the Beta Pictoris Moving Group (BPMG), which is young and nearby. We measure equivalent widths of the 6707.8 Angstrom Li I line in these stars and use them to determine lithium abundances. We combine the lithium abundance with the predictions of pre-main-sequence evolutionary models in order to calculate a lithium depletion age for each star. We compare this age to the age predicted by the HR diagram of the same model. We find that the evolutionary models under-predict the amount of lithium depletion for the BPMG given its nominal HR diagram age of ~12 Myr (Zuckerman et al. 2001), particularly for the mid-M stars, which have no observable Li I line. This results in systematically older ages calculated from lithium depletion isochrones than from the HR diagram. We suggest that this discrepancy may be related to the discrepancy between measured M-dwarf radii and the smaller radii predicted by evolutionary models.
Jensen Eric L. N.
Yee Jennifer C.
No associations
LandOfFree
A Test of Pre-Main-Sequence Lithium Depletion Models 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 A Test of Pre-Main-Sequence Lithium Depletion Models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Test of Pre-Main-Sequence Lithium Depletion Models will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-248434