How to kill a star? Astronomers observe a “destruction by collision”

astronomers have detected an immensely energetic explosion emanating from an ancient galaxyapparently triggered by a type of stellar destruction that has been hypothesized for decades but has never been observed before and might be called stellar death by collision.

According to the researchers, the observed gamma-ray burst could be due to the collision of two compact stars in a chaotic and densely populated environment, close to a supermassive black hole located in the center of the elliptical galaxy.

They suspect that the two doomed stars were neutron stars, which have about the mass of our sun in a sphere the size of a city.

“To explain the gamma-ray burst, it has to have been a compact star, not like the Sun.”explained astronomer Andrew Levan, from Radboud University in the Netherlands, lead author of the research published this week in the journal Nature Astronomy.

“Gamma-ray bursts are the most powerful in the world. universe. They release more energy per unit of time than any other known cosmic phenomenon. Therefore, its properties are truly superlative. Their name comes from the first type of light we see, gamma rays, but they actually emit the entire electromagnetic spectrum.”explains astrophysicist and study co-author Wen-fai Fong of Northwestern University.

The immense gravitational forces exerted by the black hole at the galactic center could wreak havoc, disturbing the motion of stars and other nearby objects and increasing the chances of a collision — something akin, the researchers say, to a demolition.

“Most of the stars in the universe die in a predictable way, based simply on their mass.” Levan explains. “This research shows a new pathway of stellar destruction.”

Very massive stars – more than 10 times the mass of the Sun – die in a supernova explosion, leaving behind neutron stars or even denser black holes, whose gravitational pull is so strong that neither matter nor light can escape. . Relatively low-mass stars, such as our Sun, swell and shed their outer layers, becoming a stellar remnant called a white dwarf.

“The idea that stars can also be killed by collision in extremely dense regions has been around since at least the 1980s. So we’ve been waiting 40 years for the signals to be detected by observations,” Levan explains.

The researchers used data from orbiting and ground-based telescopes to study the gamma-ray burst in a galaxy located about 3 billion light-years from Earth, roughly in the direction of the constellation Aquarius.

Source: Reuters