First Alien Planet Found Outside Milky Way
December 5, 2010 Leave a comment
Astronomers say they have found a planet near a star of extragalactic origin, which they say is the first planet coming from outside the Milky Way.
According to the study published in the journal Science, the Jupiter-like planet belongs to the Helmi stream, a group of stars belonging to a dwarf galaxy that was devoured by our galaxy in what astronomers called “galactic cannibalism.”
“As far as I know this is the first time a planet like this has been discovered,” Reuters quoted leader of the study from Germany’s Max Planck Institute for Astronomy Johny Setiawan as saying.
“It came to our galaxy about 6 to 9 billion years ago, so it’s like a visitor,” he added.
Found by a high-resolution spectrograph attached to a 2.2-meter telescope at the La Silla European Southern Observatory in Chile, the HIP 13044b planet is hosted by a star called HIP 13044 and lies around 2,000 light years from Earth in the southern constellation of Fornax.
“This discovery is very exciting,” said Rainer Klement of the Max Planck Institute. “Because of the great distances involved, there are no confirmed detections of planets in other galaxies. But this cosmic merger has brought an extragalactic planet within our reach.”
The finding challenges the existing theories of planet formation since it is the first time that a planet is found around an old star that is nearing its end. The unusual thing about the planet is that it has survived the “red giant phase” of its parent star which happens when a star consumes all its hydrogen fuel and expands massively into a “red giant” eating up smaller rocky planets like our Earth in the process.
“This discovery is particularly intriguing when we consider the distant future of our own planetary system, as the Sun is also expected to become a red giant in about 5 billion years,” said Setiawan.
Scientists say the HIP 13044b planet’s star parent will expand again in the next stage of its evolution finally eating the planet up. This can shed light on the future of our outer planets like Jupiter, as the Sun moves towards the end of its life.