LP 133-373: A NEW CHROMOSPHERICALLY ACTIVE ECLIPSING dMe BINARY WITH A DISTANT, COOL WHITE DWARF COMPANION

摘要

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 solar mass and 0.33 ± 0.02 solar radius. 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 solar mass, which would make the system at least 3 Gyr old.