Andromeda XXXV is only about 20,000 times more massive than our Sun—very small, even for a satellite galaxy. For comparison, the Milky Way’s mass is about 1.5 trillion solar masses, and the ...

The outer disc of Andromeda (above) shows a wide variety of stars, including many Sun-like ones and older variables. Image credit: NASA, ESA and T.M. Brown (STScI), of the stars in Andromeda’s ...

Some of Andromeda's dwarf galaxies are particularly puzzling, though. Dwarf galaxies around the Milky Way, for example, either stopped forming stars billions of years ago, ...

Earlier studies often assumed Andromeda’s transverse motion was small, making a future head-on collision seem almost certain. What’s different in this study? Our study did not have any new data.