Stars, Interstellar Medium and the Galaxy Commons^™

Lp 133-373: A New Chromospherically Active Eclipsing Dme Binary With A Distant, Cool White Dwarf Companion, Todd R. Vaccaro, A. Kawka, T. D. Oswalt, I. Silver, M. Wood, J. Allyn Smith

Terry D. Oswalt

We report the discovery of the partially eclipsing binary LP 133-373. Nearly identical eclipses along with observed photometric colors and spectroscopy indicate that it is a pair of chromospherically active dM4 stars in a circular 1.6 day orbit. Light and velocity curve modeling to our differential photometry and velocity data show that each star has a mass and radius of 0.340+/-0.014 M_solar and 0.33+/-0.02 R_solar. The binary is itself part of a common proper motion pair with LP 133-374, a cool DC or possible DA white dwarf with a mass of 0.49-0.82 M_solar, which would …