Gamma² Andromedae

Gamma² Andromedae or Almach C is a star in the constellation of Andromeda. It is a member of a multiple star system of Almach. It is approximately 350 light-years from our Solar System.

The system consists of four members, Almach A, Almach Ba, Almach Bb and Almach C itself.

Name
Gamma² Andromedae (abbreviated to γ² And) is the star's bayer designation, a stellar designation where a greek letter is followed by the genitive form of its constellation name. The small number two next to the letter signs that it is the secondary star in a star system.

Almach C or BC is the common name of this star. It is followed by the letter BC to indicate that it is in a star system inside another star system, the Almach B system.

Observation
In 1778, Johann Tobias Mayer discovered that Almach was a double star. When examined in a small telescope, it appears to be a bright, golden-yellow star next to a dimmer, indigo-blue star (this star), separated by approximately 10 arcseconds. It is often considered by stargazers to be a beautiful double star with a striking contrast of color.

In October 1842, Wilhelm Struve found that Almach C was itself a double star whose components were separated by less than an arcsecond. The components are an object of apparent visual magnitude 5.5, Almach B, and a type-A main sequence star with apparent visual magnitude 6.3, Almach C. They have an orbital period of about 64 years. Spectrograms taken from 1957 to 1959 revealed that Almach B was itself a spectroscopic binary, composed of two type-B main sequence stars, Almach Ba and Almach Bb orbiting each other with a period of 2.67 days.

Position
Almach C's constellation, Andromeda. Almach C is right at the edge of the constellation, labelled γ.

The location of Almach C in the sky is shown on the left. Almach C is well overhead for observers in the northern hemisphere in the waning months of the year at about 9 p.m.

Since Almach C is in the same system of Almach, it is safe to assume that they have relatively close together, hence, you can see both star in the same place.

The coordinates of the Almach system is around 02h 03m 53.9531s, +42° 19′ 47.009″.