Infrared colors of RS CVn binaries

Abstract

IRAS 1D COADD data for 82 RS CVn systems have been analysed to obtain their magnitudes at 12 and 25 micrometers. Their colors V - (12) and (12) - (25) have been computed and discussed. For 62 stars, the excess at 12 micrometers has been derived using the information on the spectral type of their binary components and measured colors (B-V) and (R-I). It is found that RS CVn systems have genuine excess at 12 micrometers. No definite conclusion can be derived for the (12) - (25) excess.