A HIGH-PRECISION DETERMINATION OF THE RADIAL-VELOCITY OF THE G5-II GIANT BETA-LEP

We apply a null technique to measure to a high accuracy the barycentri c radial velocity of the G5 II giant beta Lep (HR 1829). We use a magn eto-optical filter as a spectroscopic bridge to determine the time at which the geocentric velocity of the star passes through zero. From da ta taken on the 1.9-m reflector at the South African Astronomical Obse rvatory (SAAO) in 1992 and 1993 January, the barycentric radial veloci ty of beta Lep is calculated to be -13.6 +/- 0.2 and -13.576 +/- 0.040 km s-1 respectively.