Over the past few decades, astronomers have found around 5,000 different “exoplanets,” planets that are not part of our own solar system. All of them come from our own galaxy, the Milky Way, however.
Now, astronomers may have spotted the first exoplanet that originated neither from our solar system nor from our galaxy, but is found in the spiral galaxy Messier 51 (M51), sometimes referred to as the Whirlpool galaxy for its distinctive appearance.
Finding exoplanets in deep space is a difficult feat, especially from other galaxies. For comparison, almost all of the other previously discovered exoplanets were within 3,000 light years of Earth. On the other hand, the new planet of M51 is about 28 million light years away.
The results of the study that led to the discovery of the exoplanet have been published in a new article in the journal Nature astronomy. Researchers at the Harvard & Smithsonian Center for Astrophysics in Cambridge (CfA), Mass., Conducted the study using NASA’s powerful 22-year-old Chandra X-ray Observatory.Location of the exoplanet within the spiral galaxy Messier 51. Credit: Center for Astrophysics at Harvard & Smithsonian in Cambridge (CfA)
“We are trying to open a whole new arena to find other worlds by looking for candidate planets at X-ray wavelengths, a strategy that allows them to be discovered in other galaxies”, Rosanne Di Stefano, lead author of the study, and an astrophysicist at the Center for Astrophysics at Harvard & Smithsonian in Cambridge (CfA) said in a statement.
Harvard researchers used the same technique used to detect thousands of other exoplanets, called transits. As a planet passes in front of its orbiting star, the star’s luminosity drops briefly, allowing astronomers to detect it.
However, due to the inherent flaw in the technique, the researchers will have to wait for the planet to pass in front of the star again to confirm their observation. Considering the distance of the planet from Earth, this could take a long time.
“Unfortunately, to confirm that we are seeing a planet, we will probably have to wait decades to see another transit,” Nia Imara, co-author of the article and researcher at the University of California at Santa Cruz said in a statement. . “And due to the uncertainties about how long it takes to orbit, we wouldn’t know exactly when to look. “
Cover image: Harvard & Smithsonian Center for Astrophysics in Cambridge (CfA)