DETECTION OF A WHITE-DWARF COMPANION TO THE HYADES STARS HD-27483

We observed with IUE a white dwarf (WD) companion to the Hyades F6 V b inary stars HD 27483. This system is known to be a close binary of two nearly equal stars with an orbital period of 3.05 days. Our IUE obser vations revealed the presence of a third star, a white dwarf with an e ffective temperature of 23 000 +/- 1 000 K and a mass of approximately 0. 6 M.. Its presence in the Hyades cluster with a known age permits me to derive the mass of its progenitor, which must have been about 2. 3 M.. The presence of the white dwarf in a binary system opens the pos sibility that some of the envelope material, which was expelled by the WD progenitor, may have been collected by the F6 stars. We may thus b e able to study abundance anomalies of the WD progenitor with known ma ss on the surface of the F6 companions.