An international team of astronomers has just made a fascinating discovery: a young and bright star to escape in a hurry for our galaxy . And in addition to a rate of more than two million km/h, which makes one of the stars fastest ever observed .
What could have happened to this star flee so quickly from their "home", despite the enormous gravity of the Milky Way? According to the study published by scientists in Astronomy & Astrophysics, what has happened is that the young star is sought to a very bad company, the a black hole is very hungry . And of a type, in addition, never seen until now.
The star, call PG 1610+062 , was observed for the first time, crossing quickly the sky during astronomical observation in 1986, though since then little had been seen of her. Now, the authors of the study, astronomers of the observatory W. M. Keck in Hawaii, have had occasion to observe with more detail to the fugitive. And have confirmed that they are leaving the galactic disk at a rate that makes it one of the fastest stars views up to now.
The team, in effect, has calculated that the young sun is moving nearly two million km/h, which is not enough to escape completely from the gravity of the galaxy, but if you fast enough to leave the solar system to which it belongs, and get lost in the interstellar space.
Kick gravitationalThere are several ways of explaining how a star can be expelled from your source system. The most current is that he is part of a binary system (two stars that orbit around a common center of mass), and that your companion has exploded as a supernova, or has been absorbed by a supermassive black hole. In both cases, the star remaining would receive a "kicked due to gravity" , so suddenly and forcefully that he would be fired from its native system, or even your galaxy.
But in the case of PG 1610+062 is different. Judging by the speed, mass, and the probable origin of the star (tracked by astronomers until the spiral arm of Sagittarius of our galaxy), it seems unlikely that our fugitive is closer enough to the supermassive black hole at the center of the Pathway Lácter and see there how his partner was engulllida for him.
If it had been, in addition, our star would be moving much faster even than it does. Instead, the researchers believe that PG 1610+062 must have crossed with something much stranger: a black hole of intermediate mass, with a few hundreds of thousands of times the mass of the Sun, and not with several million times as is the case of supermassive black holes. (Sagittarius A*, the central hole of our Milky Way galaxy, has a mass equivalent to four million suns).
More testsIs it the case that until now no one has yet found convincing evidence that such black holes exist. We know those of "stellar-mass", that gather in a few km the mass of several tens of suns; and also the supermassive at the center of galaxies and have masses that can become billions of times higher than that of the Sun. But no one has seen even an intermediate-mass black hole.
The star fugitive is not, yet, a convincing proof of the existence of these black holes, but reinforces the possibility that such "monsters" of the hundreds of thousands of solar masses are really "out there". Now, says Andreas Imgang, the main author of the research, "the race to find them has begun".
Date Of Update: 16 September 2019, 12:00
