# A New Low-Mass Eclipsing Binary from SDSS-II

### Abstract

We present observations of a new low-mass, double-lined eclipsing binary system discovered using repeat observations of the celestial equator from the Sloan Digital Sky Survey II. Using near- infrared photometry and optical spectroscopy we have measured the properties of this short-period [P = 0.407037(14) days] system and its two components. We find the following parameters for the two components: M$_1$ = 0.272 +/- 0.020 M$_☉$, R$_1$ = 0.268 +/- 0.010 R$_☉$, M$_2$ = 0.240 +/- 0.022 M$_☉$, R$_2$ = 0.248 +/- 0.0090 R$_☉$, T$_1$ = 3320 +/- 130 K, and T$_2$ = 3300 +/- 130 K. The masses and radii of the two components of this system agree well with theoretical expectations based on models of low-mass stars, within the admittedly large errors. Future synoptic surveys like Pan-STARRS and LSST will produce a wealth of information about low-mass eclipsing systems and should make it possible, with an increased reliance on follow-up observations, to detect many systems with low-mass and substellar companions. With the large numbers of objects for which these surveys will produce high-quality photometry, we suggest that it becomes possible to identify such systems even with sparse time sampling and a relatively small number of individual observations.

Publication
Astrophysical Journal