Perhaps the first planet outside our galaxy has been observed. It would be about the size of Saturn and is located in the galaxy Messier 51, 28 million light years away. Authors of the discovery an international group led by the Harvard-Smithsonian Center for Astrophysics in Cambridge, USA, which published the results in Nature Astronomy.
The discovery thanks to the Chandra space telescope
The discovery was made using an innovative method that studies X-rays observed by NASA’s Chandra Space Telescope. The new observation, explains the NASA website, is based on the transits of planets, when the passage of a planet in front of a star blocks part of the star’s light and produces a characteristic decrease in brightness that can be detected by telescopes.
The first exoplanet observed outside the Milky Way
Exoplanets, such as the one observed, are defined as planets outside our Solar System. Until now, astronomers have found all of the other exoplanets within the Milky Way, nearly all within about 3,000 light-years from Earth. An exoplanet that is located in the galaxy M51 would be about 28 million light years away, which means that it would be thousands of times farther than those of the Milky Way.