I am wondering what the brightest individual star is in M31, the Andromeda Galaxy. Specifically, brightest as seen from Earth (so relative magnitude).
The Variable stars that Hubble studied in M31 when he showed that it was a galaxy are among the most luminous. They include Var-A1, a luminous blue variable, and magnitude about 16.5. Var A-1 is one of the most luminous stars known.