2021-09-03

Astronomers have discovered a new type of supernova caused by a black hole or neutron star prematurely hitting a companion star

By yqqlm yqqlm

Visit: Alibaba Cloud “88 Bang Bang Festival”: free access to business plan, communication copywriting, and smart accounting tools

Astronomers have discovered a new type of supernova caused by a black hole or neutron star prematurely hitting a companion star

This story began in 2017, when astronomer Dillon Dong of the California Institute of Technology discovered in the data collected by the VLA sky survey After receiving a strange signal, the survey is constantly scanning the universe, looking for wireless power. This particular signal, named VT 1210+4956, is an extremely bright radio wave pulse.

Dillon Dong calculated that the most likely cause of this signal is a star that is becoming a supernova, produced when the ejected material interacts with the gas envelope that the star shed hundreds of years ago Radio signal. But this is not like the whole story.

Anna Ho, another astronomer at the California Institute of Technology, suggested that the clue may lie in another type of signal besides radio. Therefore, the research team searched a single short-lived X-ray event catalog and found an event that coincides with the wireless power supply VT 1210+4956 in space, but a few years earlier.

Dillon Dong said: “These two events have never been related to each other, and on their own, they are very rare.” So, what kind of event would produce such radio and X-ray emission at the same time Woolen cloth? After extensive modeling, the team finally determined an interesting plan.

Astronomers hypothesized that the star is surrounded by a dense stellar remnant. It may be a black hole, but it may also be a neutron star. The extreme gravity of this celestial body sucks gas from the star over time, throwing some of it into space, forming a “doughnut” shape around the star.

Eventually, the remains of the star will be “pulled into” the star, causing it to burst into a supernova a long time ago. When the star collapses, a strand of matter will be ejected from its core, producing an X-ray signal. A few years later, the explosion from the exploding star will reach the gas “doughnut” around it, producing a burst of radio waves discovered by the VLA sky survey instrument. This kind of supernova caused by the merger has long been predicted to exist, but it has never been detected before.

“Massive stars usually explode into supernovae when they run out of nuclear fuel,” said Gregg Hallinan, professor of astronomy at the California Institute of Technology. “But in this case, an’invading’ black hole or neutron star prematurely triggered the explosion of its companion star.”

This research will be published in the journal Science.