Alpheratz is a blue and white star in Andromeda
A bright star
Looking at the constellation Andromeda, many of us immediately think of the beautiful galaxy M31. This is the closest galaxy to our solar system. In addition, there are interesting stars to observe. One of them is a binary star named Alpheratz. This star represents the head of the constellation Andromeda. Because of this, Alpheratz is not hard to find. The diameter of the star is approximately 4,692,770 kilometers and the star is 3.37 times larger than the Sun. With an apparent magnitude of 2.07, this star is 97 light-years from Earth. Alpheratz is the 55th brightest star in the night sky. However, it cannot be said that it is also dominantly the brightest star of Andromeda. Mirach has the same 2.07 apparent magnitude. Because of this, from Earth these stars shine with the same intensity and are easy to find.
Alpheratz is a binary star
Alpheratz is a binary star, but he also appears as one star with the naked eye and a telescope. The two stars are extremely close. Therefore, we see Alpheratz only as one star. These stars orbit every 96 days. But the stars have another companion with an apparent magnitude of 10.8. However, it is 1360 light-years away and is not physically attached to Alpharetz. The dominant star in this system is the blue and white giant. With a rotation speed of 52 km / s, Alpheratz shines 240 times brighter than the Sun. In conclusion, the surface temperature of the Alpheratz star has been calculated to be 15000 K.