NSVS07394765: A new low-mass eclipsing binary below 0.6 M_sun

Abstract

The multi-color photometric and spectroscopic (based on observations obtained with the T{\"U}B{\.I}TAK National Observatory 1.5-meter telescope, which is owned and operated by the T{\"U}B{\.I}TAK) observations of the newly discovered eclipsing binary NSVS 07394765 were obtained. The resultant light and radial velocities were analysed and the global parameters of the system: T$_{1}$=3 300 K; T$_{2}$=3 106 K; M$_1$=0.36 M$_{\odot}$; M$_2$=0.18 M$_{\odot}$; R$_1$=0.46 R$_{\odot}$; R$_2$=0.50 R$_{\odot}$; L$_{1}$=0.030 L$_{\odot}$; L$_2$=0.026 L$_{\odot}$; $i=89.2{^\circ}$; $a=5.97$ R$_{\odot}$; $d=28$ pc. The chromospheric activity of its components is revealed by strong emission in the H$\alpha$ line and observed flares. Empirical relations for mass-radius and mass-temperature are derived on the basis of the parameters of known binaries with low-mass dM components.