SDSS121258.25-012310.1 : a new eclipsing post common envelope binary

From optical photometry we show that SDSS121258.25-012310.1 is a new eclipsing post common envelope binary with an orbital period of ~ 8.06 hours and eclipse length of 23 minutes. From spectroscopic follow up observations we measured the semi-amplitude of the radial velocity for the secondary star, K2 = 181 ± 3 kms-1. By fitting the optical SDSS spectrum we constrained the stellar parameters. The white dwarf temperature is 17700 ± 300 K, its surface gravity log g = 7.53 ± 0.2, the spectral type of the secondary star is M4 ± 1 and the distance to the system d = 230 ± 20 parsec. Masses are estimated to be in the range 0.25 − 0.38 M for the red dwarf and 0.33 − 0.48 M for the white dwarf. We finally discuss the evolutionary state of the system