Astronomers have put together the fascinating story of a century of life dance of death between two massive stars, 500 million light-years away. This is according to the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, which announced the new work on September 2, 2021. Evidence suggests that a black hole or neutron star was exhaling in the core of the his companion star. In doing so, it caused the companion to explode like a supernova. Caltech astronomer Dillon Dong, lead author of a new paper reporting the discovery, commented:
Theorists had predicted that this could happen, but this is the first time we see it.
The newspaper reviewed in pairs Science published the study on September 3rd.
Data from the VLA (Karl G. Jansky Very Large Array), a radio observatory near Socorro, New Mexico, revealed these astronomers. A multi-year project called VLASS (Very Large Array Sky Survey) began at VLA in 2017. Dillon Dong and colleagues were examining VLASS images. They noticed that an object was glowing brightly on the radio waves. But, they realized, this object had not appeared in a previous VLA survey. At that moment, they felt curious.
So they looked further into the object, which is designated VT 1210 + 4956. For the new observations, they used both the VLA and the Keck Telescope in Hawaii. They determined that the bright radio emission of VT 1210 + 4956 came from the outskirts of a distant star-forming galaxy, about 500 million light-years from Earth. Looking further, they later discovered that in 2014, an instrument aboard the International Space Station had also detected an X-ray explosion from VT 1210 + 4956. NRAO explained:
The data from all these observations allowed astronomers to unite the fascinating story of a centuries-old death dance between two massive stars. Like most stars that are much more massive than our sun, these two were born as a binary pair. Narrow orbits orbit each other. One of them was more massive than the other and evolved more rapidly during its normal life, fueled by nuclear fusion. It first exploded like a supernova. And he left behind a black hole or a super-dense neutron star.
The black hole or orbit of the neutron star was constantly approaching [the second star], his companion. And, about 300 years ago [from our earthly perspective] the black hole or neutron star entered the [second star’s] atmosphere, beginning the dance of death. At this point, an interaction was initiated that sprayed the gas from the [second star] in space. The expelled gas, spiraling outward, formed an expanding ring in the shape of a donut, called a bull, around the two stars.
Finally, according to astronomers, the black hole or neutron star headed for the nucleus of the second star. It interrupted the nuclear fusion that allowed the second star to shine and kept its collapsed core under its own gravity. Without fusion, the core of the second star collapsed and exploded like a supernova. Dong explained:
The companion star was finally going to explode. But this merger accelerated the process.
The material ejected by the 2014 supernova explosion moved much faster than the previously released material from the companion star. When VLASS observed the object, the supernova explosion collided with this material, causing strong shocks that produced the brilliant radio emission seen by the VLA. Gregg Hallinan of Caltech explained:
All the pieces of this puzzle fit together to tell this amazing story. The remnant of a star that exploded a long time ago sank into its companion, causing it to explode as well.
In short: the collision of stars causes the supernova. Dramatic evidence that a black hole or a neutron star spiraled toward the core of an accompanying star and … boom!
Source: A transient radio source consisting of a supernova of core collapse caused by fusion
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