Evidence for periodic radial velocity variations in Arcturus

Abstract

The authors report evidence for periodic radial velocity variations in Arcturus; the most likely period and amplitude for these variations are 1.842±0.005 days and 160±10 m s<SUP>-1</SUP>, respectively. Observations of Pollux taken on many of the same nights show no significant power on time scales between 2 days and 2 months; the nightly accuracy of these data is ±18 m s<SUP>-1</SUP>. Epoch-folding 31 nights of Arcturus data taken between 1985 December 21 and 1986 March 31 reveals a "sawtooth" phase diagram.