G objects: a new and strange celestial body in our galaxy

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Near the supermassive black hole in the center of our galaxy, astronomers have discovered something that has baffled them: it is a type of celestial body unknown until now, which looks like gas but behaves like a star , and they have baptized as G. objects

The results of the observation over two decades of these strange objects, which most of the time are compact and expand when they approach the black hole , are published this week in the journal Nature .

It was in 2005 when the team of researchers led by astronomer Andrea Ghez, from the University of California, Los Angeles (UCLA), identified an unusual object in the center of the Milky Way, which was later called G1.

Seven years later, German astronomers also discovered in the center of our galaxy another foreign object, which they called G2, and which in 2014 approached the supermassive black hole Sagittarius A *. Ghez and his team believe that probably the origin of G2 is actually two stars that had been orbiting this black hole together and that had merged , resulting in an extremely large star, surrounded by a thick cloud of gas and dust.

When G2 made its closest approach to the black hole, its appearance became even stranger: " When it was already near the black hole it became more elongated and much of the surrounding gas broke down. And now it is becoming more compact again." , Ghez explained in a statement.

Subsequently they have discovered more objects of this type, which they have called G3, G4, G5 and G6. They have located others that could belong to this class of objects, although they continue to analyze them.

The orbits that follow these objects around the black holes range between 100 and 1,000 years, according to Ana Ciurlo, lead author of the study and also a researcher at UCLA. G1 and G2 have similar orbits while those of the other four are very different, as they have concluded after observations made from the WM Keck Observatory in Hawaii.

The fusion of a binary star

Ghez believes that the six G objects were in the past binary stars (a system of two stars that orbit each other) and that they merged due to the strong gravitational attraction that the black hole exerts . A two-star merger process takes more than a million years to complete, according to Ghez, who believes that these types of mergers could be occurring in the universe more frequently than previously thought, and could even be a fairly common phenomenon. .

His theory is that it is possible that black holes are the engine that leads binary stars to merge: "It is possible that many of the stars that we have been observing and have not understood were the end result of fusion processes that are already calm down We are finding out how galaxies and black holes evolve The way in which the two stars of a binary system interact with each other and with the black hole is very different from the way in which an individual star is related to another individual star and the black hole, "says the scientist.

Although this population of objects is at the center of our galaxy, they are very far from us, about 26,000 light years from Earth. The center of the Milky Way is a very different and much more extreme environment than the Solar System. The density of stars is one billion times greater than in our region of the galaxy: "The gravitational attraction is much greater and the magnetic fields are much more extreme. In the center of the galaxy is where extreme astrophysical phenomena take place," Astronomer points out.

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