A cow-like supernova is compared to a normal supernova. Bill Saxton is the NRAO/AUI/NSF.
The new "Cow" class of supernova explosions has a bright one. The Cow class of supernovae has only found five events so far. The group was named after the first supernova found in this class, AT2018cow, whose randomly generated name just happened to spell the word "cow."
What is behind these stellar explosions? There is new evidence pointing to either black holes or stars.
A black hole or a dead stellar remnant are left behind when a massive star explodes. These stellar remnants are usually inactive and shrouded by material ejected in the explosion. According to Yuhan Yao, a graduate student at Caltech, Cow-like events emit high-energy X-ray emission and have at their core very active, and mostly exposed, compact objects. The new findings were presented at the American Astronomical Society meeting.
She says that the birth of black holes and neutron stars can be seen from the heart of the explosions.
The stellar explosion of the first Cow event was 10 times brighter in visible light than typical supernovae and faded more quickly. It gave off a lot of highly variable X-rays, which led to the belief that they were witnessing the birth of a black hole or a neutron star for the first time.
Cows throw off a lot of mass before they explode, and this mass gets illuminated after the explosion. When the stars blow up, they generate 888-269-5556 888-269-5556 888-269-5556 888-269-5556 888-269-5556 888-269-5556 888-269-5556.
AT2020mrf is the first to be found in X-rays. The event was spotted in July 2020 using X-ray data from the Russian-German Spektrum- Roentgen-Gamma telescope. They checked the observations taken by the ZTF, which operates from Caltech's Palomar Observatory, and found that they had also spotted the event.
The initial explosion shined with 20 times more X-ray light than the original Cow event. The Chandra X-Ray Observatory data showed that the explosion was still sizzling but shining with 200 times more X-ray light than the original Cow event.
I didn't believe the analysis when I saw it. I reran the analysis many times. This is the most powerful Cow supernova to date.
The location of AT2020mrf is visible in the images from the eROSITA X-ray telescope. There was a new source between July 21 and July 24, 2020. The left panel shows that the source wasn't there six months earlier. Credit: Pavel Medvedev.
Astronomers say that the debris of the supernova must be powered by the X-ray radiation.
The large amount of energy release and the fast X-ray variability seen in AT2020mrf provide strong evidence that the central engine is either a very active black hole or a rapidly spinning neutron star. "In Cow-like events, we don't know why the central engine is so active, but it probably has something to do with the type of progenitor star being different from normal explosions."
The new class of supernovae is more diverse than originally thought because this event did not look like the other four Cow-like events. She says that finding more members of this class will help narrow down the source of their power.
The study was submitted to the Astrophysical Journal.
The X-ray and Radio Loud Fast Blue Optical Transient AT2020mrf: Implications for an Emerging Class of Engine-Driven Massive Star Explosions was written by Yuhan Yao.
The Astrophysical Journal has information.
Astronomers found the most luminous supernova explosion to shine in X-rays on January 11.
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