Scientists may have discovered the first planet outside our galaxy

The Chandra X-ray Observatory may have discovered the first exoplanet outside our galaxy.

At the moment, the found object is a candidate for exoplanets, that is, in the future, scientists would have to try to confirm its essence with the help of other space instruments. However, everything is not so simple here, but more on that below.

The object was discovered in the binary star system M51-ULS-1 in the galaxy Messier 51 (M51), located at a distance of about 28 million light years from us. By the way, this was the first of the discovered galaxies, for which the spiral structure was confirmed.

At the moment, all the exoplanets we have discovered are inside our galaxy. Moreover, most of them are located at a distance of less than 3000 light years from us. This makes the discovery even more significant.

The potential exoplanet was discovered by the transit method. This is the most effective method at the moment, based on the change in the luminosity of a star when an exoplanet passes in front of it. In this case, the only nuance is that the change in the star’s luminosity in the X-ray range was monitored.

This method has an advantage. The bottom line is that the area emitting X-rays is very small, so a planet passing in front of the star can block most of the radiation or even completely block it out. This makes it possible to detect such signals at great distances, which is extremely difficult to do in the case of observations in the visible range.

This case is also interesting because one of the components of the binary system M51-ULS-1 is a neutron star or a black hole. And a planet orbiting such an exotic pair is interesting in itself. NASA notes that if it is an exoplanet, it probably had a very turbulent past. She at least had to survive a supernova explosion, which resulted in the formation of a neutron star or black hole in M51-ULS-1. Moreover, in the future this planet can expect another similar event, since the second component of the star system – a massive star 20 times heavier than the Sun – can also explode.

Among other things, scientists were able to determine the approximate size of the object – it is close to Saturn. The distance of an object from its parent star or black hole is estimated at about 20 astronomical units.

However, there is a big problem in this situation. The distance of a potential exoplanet from a star is so great that a year on the planet is about 70 years. And this means that it is simply impossible to confirm the presence of the planet in the system earlier than in these very 70 years using at least a transit method.