Detection of a classical $\delta$ Scuti star in the new eclipsing binary system HIP 7666

HIP 7666 is a variable star newly discovered during the Hipparcos mission and classified as of unknown type (ESA 1997, The Hipparcos and Tycho Catalogues, ESA SP-1200). During 23 nights between July 2000 and November 2000, over 2300 CCD observations in the V band were obtained. These data show that the new variable is a detached eclipsing binary system with an orbital period of 2.37229 days. In addition, one of the components undergoes very short-period oscillations with a main pulsation frequency of 24.46 or 25.47 c/d. HIP 7666 is therefore a new member of the rare group of detached eclipsing binary systems with a δ Scuti type component.