Astronomers have found an alien planet confirmed to come from another galaxy for the first time, a new study finds.
The Jupiter-like planet orbits a star that was born in another galaxy and later captured by our own Milky Way sometime between 6 billion and 9 billion years ago, researchers said. A side effect of the galactic cannibalism brought a faraway planet within astronomers' reach for the first time ever. [Illustration of the extragalactic planet]
"This is very exciting," said study co-author Rainer Klement of the Max-Planck-Institut fur Astronomie (MPIA) in Heidelberg, Germany. "We have no ability to directly observe stars in foreign galaxies for planets and confirm them."
Stars currently residing in other galaxies are simply too far away, Klement added.
The find may also force astronomers to rethink their ideas about planet formation and survival, researchers said, since it's the first planet ever discovered to be circling a star that is both very old and extremely metal-poor. Metal-poor stars are lacking in typically lack elements heavier than hydrogen and helium.
The newfound planet, called HIP 13044b, survived through its star's red-giant phase, which our own sun will enter in about 5 billion years. So studying it could offer clues about the fate of our solar system as well, researchers said.
HIP 13044b sits extremely close to its parent star, which has now contracted again. The planet completes an orbit every 16.2 days, and it comes within about 5 million miles (8 million kilometers) of its parent star at closest approach — just 5.5 percent of the distance between Earth and the sun.