The Sun is quite an isolated star. Its nearest stellar neighbor, Proxima Centauri, is located 4.2 light years away. However, recent studies indicate that most stars form in pairs or even in multiple star systems. Astronomers have found that this process often begins in "stellar nurseries"—giant clouds of gas and dust that give rise to protostars.
One of the researchers studying this process is Sarah Sadavoy, an astrophysicist from Queen's University in Canada. She is investigating the Perseus molecular cloud—a "nursery" where young stars are formed. Her findings confirmed that protostars are more frequently formed in pairs.
“You get small density bursts within these cocoons, and they can break apart and form multiple stars, which we call the fragmentation process,” says Sadavoy. “If they are very far apart, they might never interact. But if they are nearby, gravity has a chance to keep them together.”
However, many of these stars lose their connection within the first few million years. Sadavoy suggests that this might have happened with our Sun.
“If we really formed with a companion, then we lost it,” she adds.