We present an analysis of a new , detached , double-lined eclipsing binary system with K7 Ve components , discovered as part of the University of New South Wales Extrasolar Planet Search .
The object is significant in that only 6 other binary systems are known with comparable or lower mass .
Such systems offer important tests of mass–radius theoretical models .
Follow-up photometry and spectroscopy were obtained with the 40-inch and 2.3m telescopes at SSO respectively .
An estimate of the radial velocity amplitude from spectral absorption features , combined with the orbital inclination ( 83.5 ^ { \circ } ) estimated from lightcurve fitting , yielded a total mass of M _ { total } = 1.041 \pm 0.06 M _ { \sun } and component masses of M _ { A } = 0.529 \pm 0.035 M _ { \sun } and M _ { B } = 0.512 \pm 0.035 M _ { \sun } .
The radial velocity amplitude estimated from absorption features ( 167 \pm 3 km s ^ { -1 } ) was found to be less than the estimate from the H _ { \alpha } emission lines ( 175 \pm 1.5 km s ^ { -1 } ) .
The lightcurve fit produced radii of R _ { A } = 0.641 \pm 0.05 R _ { \sun } and R _ { B } = 0.608 \pm 0.06 R _ { \sun } , and a temperature ratio of T _ { B } / \mbox { T } _ { A } = 0.980 \pm 0.015 .
The apparent magnitude of the binary was estimated to be V = 13.9 \pm 0.2 .
Combined with the spectral type , this gave the distance to the binary as 169 \pm 14 pc .
The timing of the secondary eclipse gave a lower limit on the eccentricity of the binary system of e \geq 0.0025 \pm 0.0005 .
This is the most statistically significant non-zero eccentricity found for such a system , possibly suggesting the presence of a third companion .