Comments on the variability and physical parameters of the F supergiant Phi Cassiopeiae

Abstract

UBVRI and uvby photometry and radial velocities have been obtained for the F0 Ia supergiant Phi Cas. The variability is confirmed from the radial velocities; the velocity range is small (Delta V/subr of about 6 km/s). No indication is found of strict periods longer than 15 days. The physical parameters Te = 7300 K + or - 300 K, R = 245 + or - 45 solar radii, and log g = 0.9 + or - 0.2 are estimated.