The Interferometric Binary Epsilon Cancri in Praesepe: Precise Masses and Age
Abstract
We observe the brightest member of the Praesepe cluster, Epsilon Cancri, to precisely measure the characteristics of the stars in this binary system, en route to a new measurement of the cluster's age. We present spectroscopic radial velocity measurements and interferometric observations of the sky-projected orbit to derive the masses, which we find to be M_1/M_sun = 2.420 +/- 0.008 and M_2/M_sun = 2.226 +/- 0.004. We place limits on the color-magnitude positions of the stars by using spectroscopic and interferometric luminosity ratios while trying to reproduce the spectral energy distribution of Epsilon Cancri. We re-examine the cluster membership of stars at the bright end of the color-magnitude diagram using Gaia data and literature radial velocity information. The binary star data are consistent with an age of 637 +/- 19 Myr, as determined from MIST model isochrones. The masses and luminosities of the stars appear to select models with the most commonly used amount of convective core overshooting.
Keywords
Cite
@article{arxiv.2205.10690,
title = {The Interferometric Binary Epsilon Cancri in Praesepe: Precise Masses and Age},
author = {Leslie M. Morales and Eric L. Sandquist and Gail H. Schaefer and Christopher D. Farrington and Robert Klement and Luigi R. Bedin and Mattia Libralato and Luca Malavolta and Domenico Nardiello and Jerome A. Orosz and John D. Monnier and Stefan Kraus and Jean-Baptiste Le Bouquin and Narsireddy Anugu and Theo Ten Brummelaar and Claire L. Davies and Jacob Ennis and Tyler Gardner and Cyprien Lanthermann},
journal= {arXiv preprint arXiv:2205.10690},
year = {2022}
}
Comments
46 pages, 15 figures