The new pre-cataclysmic binary PG 2200+085

Abstract

Aims. We present the results of spectroscopic- and orbit-sampled photometric observations of the faint UV-excess object PG 2200+085. Methods. The optical CCD photometry observations of this object were performed by the Russian-Turkish 1.5-m telescope RTT150 at the TUBITAK National Observatory (Turkey). The long-slit optical spectroscopy observations with 2.6 Å resolution were carried out by 6-m telescope BTA at the Special Astrophysical Observatory (Russia). Results. The photometric variations over two nights are almost sinusoidal with an amplitude Δm v =0 m.04 and a period of P = 0.3186 d. Such a light curve is typical of a detached close binary with an illumination effect or the ellipsoidal deformation of a secondary star. The observed spectrum clearly displays a featureless blue continuum of a hot component and a rich absorption-line and molecular band K-star spectrum. The Call line profiles with strong emission cores are remarkably similar to those of V471 Tau. Conclusions. We tentatively classify PG 2200+085 as a pre-cataclysmic binary of the V471 Tau type. © ESO 2006.