IUE observations of HD 164615.

Abstract

It is seen that HD 164615 with its spectral type F2 IV-V and (B - V) = 0.34 mag must be an exception to the rule that stars earlier than about F7 V cannot develop large spots. Abt, Bollinger and Burke (1983) found a periodic modulation of its brightness by 0.05 magnitude which they interpreted as resulting from the rotation of dark spots across the stellar disk. There is no evidence in the IUE spectra for enhancement of the ultraviolet chromospheric and transition-region emission normally associated with spots.