Scientists discover pair of stars that will cause kilonova explosion

February 3, 2023  20:48

A group of American scientists told of a stellar system consisting of two stars, in which in a few million years there will be an explosion of kilonova (this explosion, accompanied by the merger of two neutron stars). The energy released in such an explosion could be a thousand times greater than the energy released in the creation of a new star.

One of the stars in this system, 11,400 light-years away, is the neutron star called SGR 0755-2933. At the end of its life, the star had had given so much material to its companion that it no longer had enough material to end its life with a bright explosion characteristic of a supernova. Instead, it limited itself to a "quiet" explosion (a rare cosmic event), after which it turned into a neutron star.

The second star of the pair under study is called CPD-29 2176 and makes one complete revolution around its companion in 60 Earth days. This system in the constellation Puppis was accidentally discovered by Clarissa Pavao, a student at Embry-Riddle Aeronautical University in Arizona, USA, while studying data from the Sorro-Tololo Inter-American Observatory in Chile.

The unusual regular circular orbit of the massive star caught the researchers' attention. "Quiet" explosion of its companion star was not powerful enough to put it in an elongated elliptical orbit, typical for such two-star systems.

SGR 0755-2933 exploded several million years ago, and astronomers believe that CPD-29 2176 has at least another million years before it undergoes a bright supernova explosion and becomes a neutron star. After that, the two neutron stars will come close for another few million years and collide with each other, causing a kilonewave explosion.

Such explosions produce huge amounts of heavy elements – platinum, xenon, uranium and gold – which are simply ejected into space. Astronomers believe that after such events, these materials remain in the interstellar medium and then form asteroids.

Previously, it was believed that there were one or two such systems in the Milky Way galaxy, but now scientists believe there are ten.

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