A New Detached M Dwarf Eclipsing Binary

Abstract

We describe a newly discovered detached M dwarf eclipsing binary system. This system was first observed by the TrES network during a long-term photometry campaign of 54 nights. Analysis of the folded light curve indicates two very similar components orbiting each other with a period of 1.12079 ± 0.00001 days. Spectroscopic observations with the Hobby-Eberly Telescope show the system to consist of two M3e dwarfs in a near-circular orbit. Double-line radial velocity amplitudes, combined with the orbital inclination derived from light-curve fitting, yield Mtotal = 0.983 ± 0.007 M☉, with component masses of M1 = 0.493 ± 0.003 M☉ and M2 = 0.489 ± 0.003 M☉. The light-curve fit yields component radii of R1 = 0.453 ± 0.060 R☉ and R2 = 0.452 ± 0.050 R☉. Although a precise parallax is lacking, broadband VJHK colors and spectral typing suggest component absolute magnitudes of MV(1) = 11.18 ± 0.30 and MV(2) = 11.28 ± 0.30.