CoRoT 102918586: a Gamma Dor pulsator in a short period eccentric eclipsing binary

Pulsating stars in eclipsing binary systems are powerful to ols to test stellar models. Binarity enables to constrain th e pulsating component physical parameters, whose knowledge drastically improves the input physics for asteroseismic studies. The st udy of stellar oscillations allows us, in its turn, to improve our understa nding of stellar interiors and evolution. The space mission CoRoT discovered several promising objects suitable for these studies, which have been photometrically observed with unprecedented accuracy, but needed spectroscopic follow-up. A promising target was the relatively bright eclipsing system CoRoT 102918586, which turned out to be a double-lined spectroscopic binary and showed, as well, clear evidence ofγ Dor type pulsations. With the aim of combining the information from binarity and pulsation and fully exploit the potential of CoRoT photometry we obtained phase resolved high-resolution spectroscopy with t he Sandiford spectrograph at the McDonald 2.1m telescope and the FEROS spectrograph at the ESO 2.2m telescope. Spectroscopy yielded both the radial velocity curves and, after spectra disent angling, the component effective temperatures, metallicity and line-of-sight proje cted rotational velocities. The CoRoT light curve was analyzed with an iterative procedure, devised to disentangle eclips es from pulsations. The eclipsing binary light curve analys is, combined to the spectroscopic results, provided an accurate determina tion of the system parameters, and the comparison with evolutionary models strict constraints on the system age. Finally, the residual s obtained after subtraction of the best fitting eclipsing bi nary model were analyzed to determine the pulsator properties. We achieved a quite complete and consistent description of the system. The primary star pulsates with typicalγ Dor frequencies and shows a splitting in period which is consistent with high order g-mode pulsations in a star of the corresponding physical parameters. The value of the splitting, in particular, is consistent wit h pulsations inl = 1 modes.