Mirach

Beta Andromedae (β Andromedae, abbreviated Beta And, β And), officially named Mirach /ˈmaɪræk/,[13][14] is a prominent star in the northern constellation of Andromeda. It is northeast of the Great Square of Pegasus and is theoretically visible to all observers north of 54° S. It is commonly used by stargazers to find the Andromeda Galaxy. The galaxy NGC 404, also known as Mirach's Ghost, is seven arc minutes away from Mirach.[15]

This star has an average apparent visual magnitude of 2.05,[2] making it the brightest star in the constellation. The luminosity varies slightly from magnitude +2.01 to +2.10.[3] Based upon parallax measurements, it is roughly 197 light-years (60 parsecs) from the Sun.[1] Its apparent magnitude is reduced by 0.06 by extinction due to gas and dust along the line of sight.

Characteristics
Beta Andromedae is a red giant with a stellar classification of M0 III.[4] Since 1943 the spectrum of this star has been one of the stable anchor points by which other stars are classified.[16] It is suspected of being a semiregular variable star whose apparent visual magnitude varies from +2.01 to +2.10.[3] At this stage of the star's evolution, the outer envelope has expanded to around 100 times the size of the Sun.[10] It is radiating 1995[10] times the luminosity of the Sun at an effective temperature of 3842 K.