The collision of stars in the heart of the galaxy leads to its death

Paris – A recent study shows that astronomers have identified a new method of death for stars that looks like a real collision at the heart of the galaxy.

“Instead of a natural end, stars may die in collisions,” said Professor Andrew Lewen of the Dutch Radboud University, lead author of the study, whose results are published in the journal “Nature.”

A star’s fate usually depends on its mass, and the astrophysicist explains, “This matter ends up with massive stars in a big explosion supernova, while stars with lower masses, like the Sun, are extinguished as white dwarfs.”

These stars, in very rare cases and in the case of neutron stars, can merge into a pair of closely related objects when they are in a binary system.

But here the matter is different, the gamma-ray burst in October 2019 was observed in a stream of enormous energy rays originating from a distant galaxy located in the direction of the Aquarius constellation.

Depending on its duration from two seconds to several minutes, such an event represents, respectively, the merger of two neutron stars or the explosion of a large supernova star, and this event is considered, its name is “GRB191019” (GRB191019) and its duration is more than a minute. One belongs to the second category.

However, astronomers have not observed any signs of a supernova in the galaxy from which the energy exploded and is located about 2 billion light-years from Earth. However, this is not surprising, because this very old galaxy almost never formed stars, and thus no longer produces massive stars that end up in supernovae.

Longer observation of this event provided the key to solving the mystery, as the event occurred very close to the galactic center, less than a hundred light-years away. By comparison, our solar system is about 27 thousand light years away. From the center of the galaxy.

Levin explains that the nucleus of this galaxy is “a very dense region, containing millions of stars that can collide or scatter.” Under the gravitational pull of the supermassive black hole lurking at the center of the galaxy.

This led the international team of researchers to conclude that the two celestial bodies that caused the gamma-ray burst “formed and met each other at different points” in the heart of the galaxy, according to the astrophysicist.

Astronomers hypothesize that such collisions, which have been hypothesized to occur regularly in such environments, are difficult to observe because the hearts of galaxies are dense regions of dust and gas.