Supernova caused by collision with dead neighbor

A collision with an extremely compact neighbor could cause not only toasted stars, but also very healthy stars to become supernovae.

When a star dies, it doesn’t happen without the necessary hustle and bustle. A supernova is the phenomenon where a star explodes in a kind of astronomical fireworks display, and lights up enormously. The most well-known type of supernova is the collapsed heart supernova. In doing so, the fuel of a massive star – with more than ten times the mass of the sun – runs out and its iron core collapses into a black hole or neutron star.

Research by Caltech astronomers suggests that there is another type of nucleus collapse supernova: one in which a star dies prematurely as a result of a collision with its already “dead” companion star.

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Signal

In 2017, researchers spotted a particularly bright pulse of radio waves in data from the Very Large Array (VLA) radio astronomical observatory. The radio signal in question, VT 1210 + 4956, is the result of a supernova. It is believed to have been created by the interaction between material thrown into space during the explosion and a cloud of gas that rocked a nearby star a few hundred years earlier.

That, the researchers write in a professional journal Scienceturned out not to be the whole story. For more clues on the exact origin of this light signal, astronomers turned to other data: X-rays. And yes: from the same source as VT 1210 + 4956, at around 500 million d light years from Earth, the x-rays appeared to have been sent into space years earlier.

Compact neighbor

Astronomers suspect that the star responsible for the supernova had a binary star: a companion that orbits the same center of gravity. This nearby star is said to have already died and orbited the star like an extremely compact black hole, or perhaps a neutron star.

The attraction of this dead neighbor is said to have sucked material from the star over the years. Some of the material was thrown into space due to the extreme rotational force of the black hole (or neutron star). There he would have formed a gas donut around the pair.

Fatal collision

Ultimately, the researchers suspect that this “dance”, in which the deceased star shoots and shoots, may have ended in an astronomical collision, where the star explodes into a supernova. The x-ray signal could be attributed to this. Years later, the material associated with this explosion would have reached the “gas donut”, resulting in the later and brilliant radio pulse.

It has been suspected for some time that such a merger could result in a supernova. However, it has never been seen like this before.

Sources: Science, Caltech, EurêkAlert!

Domain: Chuck Carter / Caltech