Star collision creates a supernova explosion never seen before

Astronomers have found evidence that a black hole or a neutron star spiraled into another nucleus and caused it to explode as a supernova, an event over which theories existed, but which so far have not been identified. ‘had identified.

The team, which publishes its results in Science today, used data from the VLASS (Very Large Array Sky Survey) sky observation project, which aims to locate transient objects.

“Of all the things we thought we’d discover with VLASS this wasn’t one of them,” noted one of the authors of the Gregg Hallinan study at the California Institute of Technology (Caltech).

Normal supernovae occur when a massive star runs out of fuel and can no longer withstand its own gravity, so its core collapses on itself, triggering a supernova explosion, which leaves behind a neutron star. or a black hole.

As most massive stars are born in binary systems, these compact objects resulting from the explosion can remain in close orbit with their companion stars and potentially spiral until they merge, but this type of event had not. observed so far.

Analyzing data from VLASS, the Haway Keck Telescope and the International Space Station, the team was able to reconstruct the story of “a dance of death that lasted centuries between two massive stars,” says the American National Radio Astronomy Observatory in a statement.

The start were two stars that were born as a binary pair and orbited very close together. One of them, which was more massive, evolved more rapidly and exploded like a supernova, leaving behind a black hole or a super-dense neutron star.

The orbit of that black hole or neutron star was getting closer and closer to that of its companion and about 300 years ago it entered its atmosphere.

Eventually, the black hole or neutron star made its way to the core of the companion star, interrupting the nuclear fusion that produced the energy that prevented the nucleus from collapsing by its own gravity.

As the nucleus collapsed, a disk of material briefly formed that orbited closely around the intruder and propelled a jet of material toward the outside of the disk at speeds close to that of light, opening -pass through the star.

“This ray is what produced the X-rays seen by the MAXI instrument aboard the International Space Station, and this confirms the date of this event in 2014,” said study lead author Dillon Dong, from Caltech.

The collapse of the star’s nucleus caused it to explode as a supernova and although it would still explode at some point, this fusion accelerated the process.

“All the pieces of this puzzle fit together to tell this amazing story,” said Hallinan, the remnant of a star that exploded a long time ago crashed on his partner, causing it to explode as well.