irregular variables

irregular variables

Stars, such as the majority of red giants, that are pulsating variables showing slow luminosity changes either with no periodicity or with a very slight periodicity. The latter can be grouped into slow irregular variables of spectral types F, G, K, M, C, and S that are usually giants, and slow irregular supergiants of spectral types M, C, and S.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006