A new sort of stellar explosion.

Astronomers have uncovered evidence of explosions triggered by dead stars crashing into living stars, suggesting a new type of supernova, according to a new study.

Supernovae are gigantic explosions that can happen whenever the stars die. These eruptions may briefly eclipse any other suns in the galaxies of these stars, making them visible midway through the cosmos.

For decades, scientists have been familiar with two main types of supernovae. Large stars more than 10 times the sun's mass collapse in their centers when their cores burn all their fuel, causing the outer layers to explode and leaving behind a stellar remnant such as a neutron star or black hole. In contrast, stars less than eight times the sun's mass burn out over time, leaving behind a dense core known as a white dwarf, and these remnants can pull fuel onto themselves off companion stars until they detonate in a thermonuclear explosion.

But scientists have suggested other types of supernovae can exist. For example, most stars with more than eight solar masses are born in orbits near each other. The heavier members of these pairs may die first as supernovas, leaving behind a neutron star or black hole that can theoretically spiral toward its partner and collide, triggering a supernova.

Astronomers may have found signs of such a fusion which triggered the collapse of the supernova. They expanded on their findings online today (seven. 2) In the journal Science.

"This is the first in a new supernovae class," Space.com.

Using data from the Very Large Array Sky Survey (VLASS), a project that scans the night sky for radio outbursts, researchers detected an extremely luminous flare of radio waves, dubbed VT J121001+4959647, that happened in 2017. This explosion was not present in previous radio reports and is "linked to the most radio-light supernova ever detected," Dong said.

Through radio and optical analyses, the researchers found that the radio flare came from a star surrounded by a thick envelope of gas. This envelope of material was probably thrown out of the star a few centuries before the radio signals were broadcast.

"The offspring star had undergone an eruptive mass loss episode, ejecting more than the sun's mass from its atmosphere,' said Mr. Dong.

The astronomers suggest the radio outburst happened when the star exploded in a supernova, with debris from the explosion crashing into the surrounding gas shell, generating a blaze of radio waves.

The scientists then reviewed the previous radiography data. They found that in 2014, X-ray sprays erupted at about the same location as VT J121001+4959647. They suggest that these jets occurred when a star turned into a supernova, leaving behind a dead star that pulled gas from its companion, generating a dense gas shell. The bright glow from the radio then happened after the dead star hit its surviving partner.

"As the neutron star or black hole sinks, it is expected to unlock a large part of the star's atmosphere and eject it over long distances," Dong said. "And if it reaches the nucleus, the theory says it can disrupt fusion, trigger a supernova, and launch the jets we've seen."

"I had no idea we would come up with such a system in VLASS," Dong said. "But that's kind of the beauty of it — we looked with open eyes at every possible interesting source and let our experience, particularly of dead ends, we've gone down in the past, and our intuition point us towards the ones to look further into."

The scientists now plan to further monitor VT J121001+4959647 to learn more about how pairs of massive stars spiral toward each other, something that is extremely difficult to model with computer simulations," Dong said. "Systems like this could help us better understand the physics of what goes on when two stories merge."

Further discoveries would wait, Dong added.

"One of the most exciting findings in astronomy of the past decade was that the most massive stars are born in binary systems, triple systems, quadruple systems, and so on, and most of them are close enough to have strong interactions within the lifetime of the star," Dong said. "Where astronomers used to model these stars in isolation, we now recognize that there is a rich set of phenomena to explore resulting from the interactions of these stars. A supernova triggered by a fusion merely grazes the surface of possibility. With the next generation of sky readings and new developments in theoretical astrophysics, we may discover that stars behave in a variety of unexpected ways."