Astronomers may have found the first planet in another galaxy, according to New Scientist magazine.
About 300 planets have been found in our own Milky Way galaxy using various methods.
But a team from the University of Zürich in Switzerland wanted to see if one of those methods, called gravitational microlensing, would work on the Andromeda galaxy, the Milky Way's neighbor and virtual twin.
Gravitational microlensing is simple in theory — as an object passes in front of a star, the object's gravity bends the star's light around itself, effectively magnifying the star.
So team leader Philippe Jetzer and his colleagues built a computer model to see how large planets — Jupiter-sized and up — would affect the light from stars in Andromeda, which is 2 million light-years away.
Surprisingly, their results matched a set of observations from Andromeda done in 2004 by another team Jetzer was involved with.
At the time Jetzer thought he'd spotted a binary star, but the results look a lot more like what his extragalactic planet model predicted for a planet 6 or 7 times the size of Jupiter.
"It plausibly could be a planet," Andrew Gould of Ohio State University, who wasn't part of either team, told New Scientist.
Unfortunately, such microlensing events occur randomly, so it might be a long time before we know for sure.