Did the Sun once have a companion star
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New evidence has suggested that all the sunlike stars in the universe may have formed together in pairs.

The findings, which were based on a recent radio survey of a giant molecular cloud full of recently formed stars in the constellation Perseus, suggest that stars do not form individually but are instead born in pairs which later drift apart around one million years later.

Intriguingly, this would also mean that our own Sun once had its own companion - a star often referred to as 'Nemesis' and for which astronomers have been searching for years.

"We are saying, yes, there probably was a Nemesis, a long time ago," said study co-author Steven Stahler. "We ran a series of statistical models to see if we could account for the relative populations of young single stars and binaries of all separations in the Perseus molecular cloud, and the only model that could reproduce the data was one in which all stars form initially as wide binaries."

"These systems then either shrink or break apart within a million years."

A "wide binary" is a pair of stars around 500 astronomical units apart which in this case would have placed our own Sun's companion star 17 times further away from the Earth than Neptune.

At some point in the distant past it would have likely escaped and headed off in to the galaxy.

Exactly where it is now however remains a total mystery.