BAFFLES: Bayesian Ages for Field Lower-mass Stars
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 ≤ B − V ≤ 0.9 and a measurement of R′HK and/or 0.35 ≤ B − V ≤ 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.
Citation
Stanford-Moore , S A , Nielsen , E L , De Rosa , R J , Macintosh , B & Czekala , I 2020 , ' BAFFLES: Bayesian Ages for Field Lower-mass Stars ' , Astrophysical Journal , vol. 898 , no. 1 , 27 . https://doi.org/10.3847/1538-4357/ab9a35
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Description
Funding: R.D. acknowledges support from the Fonds de Recherche du Québec. Supported by NSF grants AST-1411868 (E.L.N., B.M.), and AST-1518332 (R.J.D.R.). Supported by NASA grants NNX14AJ80G (E.L.N., B.M.), NNX15AC89G and NNX15AD95G (B.M., R.J.D.R.), 80NSSC17K0535 (B.M., E.L.N., R.J.D.R), and NASA Hubble Fellowship grant HST-HF2-51405.001-A (I.C.).Collections
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