The temperature and granulation stability of N Cephei

As part of a larger long-term project to measure variations in photospheric temperature and granulation arising from rotational modulation and stellar magnetic cycles, the null results for the subgiant star eta Cep (HR 7957, HD 198149, K0 IV, B-V=0.92) in the 1989-1992 interval are reported here. Temperature variations on rotational timescales are less than 5 K, and year-to-year variations, such as those one might expect during a magnetic cycle, are less than 1.7 K. No variation is detected in the velocity span of the spectral-line bisectors above 19m/sec on rotational timescales, and any year-to-year variations must be less than 5 m/sec.