Photometric and spectroscopic observations of the F3+M3 eclipsing binary T-Lyr0-08070

The multi-color photometric and spectroscopic observations of the newly discovered eclipsing binary T-Lyr0-08070 were obtained. The resultant light and radial velocities were analysed and the absolute parameters of the components were determined. The system is composed of an F3 and an M3 main-sequence stars. Masses and radii were estimated to be 1.37 ± 0.23 M⊙M⊙ and 1.60 ± 0.09 R⊙R⊙ for the primary and 0.32 ± 0.04 M⊙M⊙ and 0.86 ± 0.06 R⊙R⊙ for the secondary star. The less massive secondary component has a radius at least two times larger with respect to its mass. Using the BVJHK magnitudes of the system we estimated an interstellar reddening of 0.22 mag and a distance to the system as 479 ± 36 pc.

► We observed M-dwarf eclipsing binary T-Lyr0-08070.
► The system is composed of an F3 and an M3 main-sequence stars.
► The secondary component has a radius at least two times larger than expected.
► This discrepancy has been well explained by stellar activity.