Presented at the Spring
Meeting of the AAVSO, May 21, 1994
Several new determinations
of times of minima based upon photoelectric measurements of the eclipsing
binary GK Cephei are reported. These measurements, together with times of
minima previously reported in the literature, permit an improvement to the ephemeris
equation for GK Cep. Analysis of O-C residuals determined from linear ephemeris
equations suggests a periodic oscillation with a period of 18.6 years.
Inclusion of a sinusoidal term in the ephemeris equation with this period
greatly improves the fit of the ephemeris equation with reported observations
of times of minima.