A team of scientists from Caltech has just described a curious phenomenon whose existence theoretically predicted, but it had never been observed. It is about the abrupt appearance of a supernova due to the collision of a black hole or a neutron star with a companion star.
The finding, reported in Science, is especially curious, since it is the result of the union of a puzzle of millions of years, which had gradually dropped its pieces throughout the last decade.
It is true that you cannot know exactly what happened. However, there is a very probable explanation, the result of which could be described as a new type of supernova.
The pieces of the puzzle that ended with a new supernova
It all started when a Caltech graduate researcher, Dillon dong, was analyzing data collected by the Very Large Array Sky Survey (VLASS), an instrument that tracks the sky by detecting signals at the radio wavelength.
The signals were recorded in 2017 and 2014
One of 2017., corresponding to an extremely bright source of radio waves, which they baptized as VTJ 121001 + 4959647. I had never seen anything like it. He observed that it came from a star surrounded by a thick and dense layer of gas, which would have been thrown by the star itself hundreds of years earlier.
As for that very luminous signal, it was something known as a radio transient, which would be generated during the explosion that gives rise to a supernova. But it was the brightest they had ever seen.
He needed more data to know exactly how something like this could have happened. And the idea, according to a statement from Caltech, was given to him by his partner Anna Ho, proposing to inspect a catalog of brief brilliant events, measured in the X-ray spectrum.
In doing so, they found a signal registered in the same place in the sky as VTJ 121001 + 4959647. It was detected in 2014 and had been called VT 1210 + 4956. It was clear that both seemed to come from the same event, but which one?
The neutron star or the black hole comes into play
To find out how the two events are related, this team of scientists conducted several computational models in which it was sought how the pieces could fit better. And they came up with what would be the most likely explanation.
The signals to the formation of a supernova by fusion had never been recorded
The chain of events would begin with the remnant of a massive star that would have exploded earlier. That is to say, a neutron star or a black hole. This object would orbit very close to another star, interacting gravitationally with it to the point of starting to divert your atmosphere and expel it into space. This would have caused that dense layer of gas that was detected around the radio transient star of 2017.
Once this happened, the black hole or neutron star got closer and closer to that star, to the point of crashing into it, engulfing it and causing the abrupt explosion that would generate the supernova and, with it, that star. first X-ray signal detected in 2014. The jet of material that was ejected from the blast would then collide with the gas cloud, generating the 2017 signal.
Usually, a supernova explosion occurs little by little, when the star runs out of the fuel that generates energy at its core. Like that, many cases have been detected. But like this nothing had been detected before. This had been theorized, but the signs of the event had not been recorded. That is why it is such an important find.