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arXiv · 2006.04811

BAFFLES: Bayesian Ages for Field Lower-Mass Stars

S Adam Stanford-Moore·Eric L. Nielsen·Robert J. De Rosa·Bruce Macintosh·Ian Czekala
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Abstract

Age is a fundamental parameter of stars, yet in many cases ages of individual stars are presented without robust estimates of the uncertainty. We have developed a Bayesian framework, BAFFLES, to produce the age posterior for a star from its calcium emission strength (log($R'_{HK}$)) or lithium abundance (Li EW) and $B-V$ color. We empirically determine the likelihood functions for calcium and lithium as functions of age from literature measurements of stars in benchmark clusters with well-determined ages. We use a uniform prior on age which reflects a uniform star formation rate. The age posteriors we derive for several test cases are consistent with literature ages found from other methods. BAFFLES represents a robust method to determine the age posterior probability distribution for any field star with $0.45 \leq B-V \leq 0.9$ and a measurement of $R'_{HK}$ and/or $0.35 \leq B-V \leq 1.9$ and measured Li EW. We compile colors, $R'_{HK}$, and Li EW from over 2630 nearby field stars from the literature and present the derived BAFFLES age posterior for each star.

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S Adam Stanford-Moore, Eric L. Nielsen, Robert J. De Rosa, Bruce Macintosh, Ian Czekala. 2020-06-16. BAFFLES: Bayesian Ages for Field Lower-Mass Stars. https://doi.org/10.3847/1538-4357%2Fab9a35

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