S Pegasi

S Pegasi (S Peg) is a Mira variable star in the constellation Pegasus. It varies between magnitude 7 and 13 with a period of 319.22 days. It is believed to be pulsating in the first overtone. First overtone pulsators have masses less than at a temperature of 2,107 K, and less than  at the luminosity of S Pegasi.