One Trillion Stars

The Milky Way is estimated to have anywhere from 100 billion to 400 billion stars, but the Andromeda Galaxy boasts around one trillion stars. NASA’s Hubble Space Telescope uncovered a large and rare population of hot, bright stars as a part of those one trillion. Blue stars are typically hot, young stars, but the blue stars found in the Andromeda Galaxy were aging, Sun-like stars that have cast out their outer layer of materials and exposed their blue-hot cores. These stars are scattered throughout the center of the galaxy and are brightest in ultraviolet light.[4]