Chi Cygni

Chi Cygni is a Mira variable star in the constellation Cygnus, and also an S-type star. Its name is a Bayer designation that is Latinized from χ Cygni, and abbreviated Chi Cyg or χ Cyg. It is around 500 light years away.

χ Cygni is an asymptotic giant branch star, a very cool and luminous red giant nearing the end of its life. It was discovered to be a variable star in 1686 and its apparent visual magnitude varies from as bright as 3.3 to as dim as 14.2, corresponding to a brightness factor of over 20,000. It is only visible to the naked eye for a short period near each maximum.