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☉ and 0.33 ± 0.02 R☉. 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☉, which would make the system at least 3 Gyr old.
The Astrophysical journal
The Institute of Physics
Scholarly Commons Citation
Vaccaro, T., Oswalt, T. D., Rudkin, M., Kawka, A., Vennes, S., & Et al. (2007). LP133-373 A New Chromospherically Active Eclipsing dMe Binary with a Distant, Cool White Dwarf Companion. The Astrophysical journal, 661(2). https://doi.org/10.1086/517872