変光星総合カタログ
The spectral type of MY Cephei is given in the General Catalogue of Variable Stars as M6–7 Iab, indicating the star is an intermediate-size luminous supergiant star, although most authors gives M7–M7.5 I. Classification is difficult because of the lack of comparable standard stars, but its spectrum appears to be later than M5, earlier than VX Sagittarii when at M9, and more luminous than M7 giant stars.