仙女座星系
Compared to the Milky Way, the Andromeda Galaxy appears to have predominantly older stars with ages &gt;7 years. The estimated luminosity of the Andromeda Galaxy, , is about 25% higher than that of our own galaxy. However, the galaxy has a high inclination as seen from Earth and its interstellar dust absorbs an unknown amount of light, so it is difficult to estimate its actual brightness and other authors have given other values for the luminosity of the Andromeda Galaxy (some authors even propose it is the second-brightest galaxy within a radius of 10 megaparsecs of the Milky Way, after the Sombrero Galaxy, with an absolute magnitude of around −22.21 or close).