Astronomers may have spotted the first planet discovered in another galaxy. The potential star, named M51-ULS-1b, orbits a “giant” and a dead star in the Whirlpool Galaxy, about 28 million light-years from Earth (one light-year is equivalent to 9.46 trillion kilometers).
A study published in the scientific journal says that if confirmed, the planet’s existence suggests that there are still many “extragalactic exoplanets” to be discovered by astronomers. nature astronomy.
“We probably always thought there were planets in other galaxies,” said astrophysicist Rosanne Di Stefano, a researcher at the University of Cambridge, in an interview published by the website. science news. “But finding something really is a beautiful thing, a lesson in humility.”
More than 4,800 planets have been discovered orbiting stars other than the Sun, but they are all part of the Milky Way. On the other hand, there is no reason to think that there are no planets outside it, the scientific media highlights.
Unfortunately, the “hunting” of planets from other galaxies is hindered by distance, as the stars end up appearing too close together and making individual observation difficult to identify planets around them.
In 2018, Di Stefano and astrophysicist Nia Imara, part of the University of California research body, suggested that these planets should be discovered by identifying “X-ray binaries,” a class of binary stars.
These pairs usually form from the remains of a single massive star and another massive star that has “collapsed” into a black hole or neutron star. The dead star “steals” material from the living one and heats it, reaching a temperature so high that it emits very bright X-rays, making it stand out from the rest of the stars.
The region emitting these rays may be smaller than that of a giant planet, so if an existing planet passes or transits in front of this binary system, changing the point of view of astronomers viewing from Earth, it will emit X-rays. Can block, “give up” its existence.
Although Di Stefano’s team tech worked on the first observation, she explains that she doesn’t expect to see M51-ULS-1b again, as it could take decades to pass in front of host stars again. “The real test is to find more planets,” concluded the astrophysicist in a statement to Science News.