While Capella appears to be a single star, it is actually a group of four stars that make up the sixth-brightest object in the night sky. The two stars that make up the brightest part of Capella have a surface temperature comparable to the Sun, about 4,900 degrees Kelvin.
The brightest aspect of Capella is made up of a pair of large type-G stars. These stars, known as Capalla Aa and Capalla Ab, are orbited at a distance of 1 light year by another binary system consisting of two red dwarfs. While many times larger than the Sun, Capalla Aa and Capalla Ab are approximately the same temperature.