HD 81410 - A new RS CVn binary

Abstract

B and V photometry of HD 81410 obtained on 34 nights between January 3 and March 14 of 1981 is presented. In both B and V, the amplitudes are found to be approximately 0.15 mag. It is also found that a 12.86833 day period satisfies all the available photometric data. Orbital elements of the system are derived from the published radial velocity measurements. The orbital period, strong Ca II H and K emission, and the spectral types of the components suggest that HD 81410 is a member of the RS CVn group. The star is seen to become redder at fainter visual magnitudes. This is attributed to the relatively cooler temperatures of the 'darker regions' present on the visible hemisphere.