New Delhi: As scientists attempt to gain a better understanding of the solar system and search for those existing beyond our own, they have often made incredible discoveries, especially those in the form of numerous exoplanets that mimic the ones in our own solar system.
Now, for the first time, a population of planets beyond the Milky Way galaxy has been discovered by a team of astrophysicists from the University of Oklahoma.
Using data from NASA's Chandra X-ray Observatory, researchers used microlensing to detect the objects in extragalactic galaxies that range from the mass of the Moon to the mass of Jupiter.
Microlensing is an astronomical phenomenon that uses the light bent by gravity itself to detect planets. It is a method capable of discovering planets at truly great distances from the Earth.
The planet population, ranging from the size of the Moon to the size of Jupiter, were spotted in a galaxy located 3.8 billion light-years away, according to the study published in The Astrophysical Journal.
"We are very excited about this discovery. This is the first time anyone has discovered planets outside our galaxy," said Professor Xinyu Dai.
"These small planets are the best candidate for the signature we observed in this study using the microlensing technique. We analysed the high frequency of the signature by modelling the data to determine the mass," Dai said.
While planets are often discovered within the Milky Way using microlensing, the gravitational effect of even small objects can create high magnification leading to a signature that can be modelled and explained in extragalactic galaxies.
Until this study published in The Astrophysical Journal Letters, there has been no evidence of planets in other galaxies.
"This is an example of how powerful the techniques of analysis of extragalactic microlensing can be," said Guerras.
"This galaxy is located 3.8 billion light-years away, and there is not the slightest chance of observing these planets directly, not even with the best telescope one can imagine in a science fiction scenario," he said.
"However, we are able to study them, unveil their presence and even have an idea of their masses. This is very cool science," Guerras said.
(With Agency inputs)