Space & Astronomy

Astronomers may have discovered first known extragalactic planet

By T.K. Randall
October 27, 2021 ·  0 comments

It is very likely that planets are common throughout the universe. Image Credit: Nick Risinger The hunt for extrasolar worlds (planets that exist outside of our solar system) has been going from strength to strength in recent years, with astronomers identifying thousands of distant worlds, including some with the potential to host alien life.

As things stand, however, we know relatively little about the prevalence of planets in other galaxies save for what can be deduced from our findings within our own Milky Way galaxy.

Now though, astronomers believe that they have found evidence of a planet outside of our galaxy, which if true would make this the first ever discovery of an extragalactic world.

Located 28 million light years away in the Messier 51 galaxy and believed to be around the size of Saturn, the new planet was spotted using NASA's Chandra X-Ray Telescope.It was detected using the transit method, which looks for a dip in the star's brightness when an orbiting planet moves in front of it, temporarily blocking some of the light.

Due to the distances involved, astronomers looked for dips in a specific type of object known as an X-ray bright binary, which is essentially a black hole or neutron star pulling in the gases from a nearby companion star.

"The method we developed and employed is the only presently implementable method to discover planetary systems in other galaxies," astrophysicist Dr Di Stefano told BBC News.

"It is a unique method, uniquely well-suited to finding planets around X-ray binaries at any distance from which we can measure a light curve."

More data will be needed, however, to confirm for sure that the observed dip was caused by an orbiting planet.

Source: BBC News | Comments (0)

Tags: Extragalactic, Planet, Milky Way