FK Comae Berenices is a variable star that varies in apparent magnitude between 8.14 and 8.33 over a period of 2.4 days. In 1966, Pavel Fedorovich Chugainov discovered that the star, then called HD 117555, varied in brightness. It was given its variable star designation, FK Comae Berenices, in 1968. It is the prototype for the FK Comae Berenices class of variable stars. The variability of FK Com stars may be caused by large, cool spots on the rotating surfaces of the stars. This star is thought to be the result of a recent binary merger, resulting in a high rate of both spin and magnetic activity.