For the first time, stars snacking on their stellar neighbors outside the Milky Way have had their orbits fully mapped. Using the Sloan Digital Sky Survey, astronomers have identified two pairs of stars beyond the galaxy that are consuming their companions. The new discovery can help astronomers understand if distant galactic environments function similarly to or differently from the Milky Way. It can also provide insight into one of the fundamental methods of measuring distance in the night sky.

More than half the stars in the Milky Way come in pairs. While it seems likely that binary stars should make up a significant fraction of other galaxies, scientists have been unable to confirm that because at such large distances ordinary stars are too faint to see.But so-called symbiotic stars, where one companion consumes the other, can be extremely bright, making them easier to observe.