Posted on 09/02/2021 11:40:43 AM PDT by Red Badger
Fast-moving debris from a supernova explosion triggered by a stellar collision crashes into gas thrown out earlier, and the shocks cause bright radio emission seen by the VLA. Credit: Bill Saxton, NRAO/AUI/NSF
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Astronomers have found dramatic evidence that a black hole or neutron star spiraled its way into the core of a companion star and caused that companion to explode as a supernova. The astronomers were tipped off by data from the Very Large Array Sky Survey (VLASS), a multi-year project using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA).
“Theorists had predicted that this could happen, but this is the first time we’ve actually seen such an event,” said Dillon Dong, a graduate student at Caltech and lead author on a paper reporting the discovery in the journal Science.
The first clue came when the scientists examined images from VLASS, which began observations in 2017, and found an object brightly emitting radio waves but which had not appeared in an earlier VLA sky survey, called Faint Images of the Radio Sky at Twenty centimeters (FIRST). They made subsequent observations of the object, designated VT 1210+4956, using the VLA and the Keck telescope in Hawaii. They determined that the bright radio emission was coming from the outskirts of a dwarf, star-forming galaxy some 480 million light-years from Earth. They later found that an instrument aboard the International Space Station had detected a burst of X-rays coming from the object in 2014.
The data from all these observations allowed the astronomers to piece together the fascinating history of a centuries-long 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, closely orbiting each other. One of them was more massive than the other and evolved through its normal, nuclear fusion-powered lifetime more quickly and exploded as a supernova, leaving behind either a black hole or a superdense neutron star.
The Sequence of Events — Clockwise, from top left: (1.) A neutron star or black hole orbits a “normal” companion star (light blue), growing closer over thousands of years. (2.) The neutron star or black hole enters its companion’s atmosphere, throwing gas outward in an expanding spiral. (3.) When the intruder reaches the companion’s core, material briefly forms a disk that propels a superfast jet outward, poking its way out of the star. The nuclear fusion that held the companion’s core up against its own gravity is disrupted, triggering a collapse and subsequent supernova explosion. (4.) The material blasted out by the supernova explosion catches up to the material thrown out by the earlier interaction, causing strong shock waves that produce the radio waves observed with the VLA. Credit: Bill Saxton, NRAO/AUI/NSF
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The black hole or neutron star’s orbit grew steadily closer to its companion, and about 300 years ago it entered the companion’s atmosphere, starting the death dance. At this point, the interaction began spraying gas away from the companion into space. The ejected gas, spiraling outward, formed an expanding, donut-shaped ring, called a torus, around the pair.
Eventually, the black hole or neutron star made its way inward to the companion star’s core, disrupting the nuclear fusion producing the energy that kept the core from collapsing of its own gravity. As the core collapsed, it briefly formed a disk of material closely orbiting the intruder and propelled a jet of material outward from the disk at speeds approaching that of light, drilling its way through the star.
“That jet is what produced the X-rays seen by the MAXI instrument aboard the International Space Station, and this confirms the date of this event in 2014,” Dong said.
The collapse of the star’s core caused it to explode as a supernova, following its sibling’s earlier explosion.
“The companion star was going to explode eventually, but this merger accelerated the process,” Dong said.
The material ejected by the 2014 supernova explosion moved much faster than the material thrown off earlier from the companion star, and by the time VLASS observed the object, the supernova blast was colliding with that material, causing powerful shocks that produced the bright radio emission seen by the VLA.
“All the pieces of this puzzle fit together to tell this amazing story,” said Gregg Hallinan of Caltech. “The remnant of a star that exploded a long time ago plunged into its companion, causing it, too, to explode,” he added.
The key to the discovery, Hallinan said, was VLASS, which is imaging the entire sky visible at the VLA’s latitude — about 80 percent of the sky — three times over seven years. One of the objectives of doing VLASS that way is to discover transient objects, such as supernova explosions, that emit brightly at radio wavelengths. This supernova, caused by a stellar merger, however, was a surprise.
“Of all the things we thought we would discover with VLASS, this was not one of them,” Hallinan said.
Reference: “A transient radio source consistent with a merger-triggered core collapse supernova” 2 September 2021, Science. DOI: 10.1126/science.abg6037
The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.
Probably going to see more and more wonders in the sky from here on...
Actually, we still haven’t seen anything like tis, if the consensus is that is/occurred 480 million light years away....
Just a blast from the past.....
That does bring up a point to ponder: Is the SOL really 186,000 MPS or is that an average of a “there and back” experiment? Maybe its “instantaneous” one way, and then 186k the other? Oh, wait, we cannot calibrate clocks nor have adequate stand off to really be precise- so international convention decrees that SOL is 186k MPS....
Look it up.
...we have not yet addressed global warming...
...racism...
...not enough people are vaccinated...
...President Trump colluded with Russia...
...domestic extremism...
...Epstein did actually kill himself...
...Hillary's server was only wiped with a cloth...
...we're not letting in enough "undocumented immigrants" along our southern border...
Does that about cover the usual leftist excuses/scapegoats?
is that a real false color image or cgi?
i can’t tell from the article
Is this something that is happening NOW or did it happen some 480 million years ago and the light and radio waves just now hitting the Earth?
So WTH happened? Did it result in a huge black hole?
Or what?
Need to know since we can send the politicos there from here.
As I understand, when you look up at the stars at night your looking back at celestial history.
Has to be a new record for old news!
Spanish Google translation: The light signal VT 1210 + 4956. It is not appreciated in 1997 (A) and yes on November 20, 2017 (20) Almost 21 years later. In (C) optical image of its location from the Hubble telescope. Dong et. to the. 2021 | Science https://www.lavanguardia.com/ciencia/20210902/7695946/descubierto-tipo-supernova-identificada-universo.html
480 million years ago, noticed in 1997, then re examined in 2020..............
Looks like the world map I couldn’t refold last summer...
Outstanding!
Too bad the 3 gravity detectors weren’t operating back then...
oh thank you very much, cause that top pic looks like cgi to me
The ‘trick to folding a map is to lay it flat of a table or floor. Then notice where the folds are ‘UP’ toward you, off the surface.
Then fold accordingly......................
Looks like a fire opal; wish I had a pendant that looks like that.
Hey, if you play your cards right, you'll see many, many more as you enjoy blissful eternity at the foot of God's throne.
Some people just have to take all the fun out of folding a map every which way but right...
;-)
Of course if you are in a car, all bets are off!...................
How true, how true...
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