MYSTERIOUS COSMIC DETONATIONS: The Cow

Mysterious Cosmic Detonations is the title of an article in the latest issue of Scientific American and the first one was named "the Cow."

• In 2018 a massive cosmic explosion made its way to us as a bright flash of blue, from a later-designated AT2018cow portion of the sky.  Thus, "the Cow."
• More scientifically, this outburst is now called a Fast Blue Optical Transient (FBOT).
• Initially there was some belief it was a supernova.
• Since then a few more have been found.
• But exactly what has confounded astrophysicists.

How does a Cow compare with a gamma-ray burst (GRB) or a supernova?

• GRBs were discovered serendipitously in 1967 by Air Force satellite Velas on the lookout for Soviet  nuclear testing violations.
• The satellites also carry a gamma-ray detector because nuclear explosions produce gamma rays.  But this glaring light came from outer space beyond our universe.
• This was the mystery of those days until scientists determined they came from the collapse of matter forming a black hole during the death of massive stars in supernovas.
• The ultra long-lasting ones of more than 30 seconds are the product of hypernovas, 100 times the brightness of supernovas, when stars 5-10 times the mass of our sun implode into black holes.
• 
  Gamma-ray bursts are the product of what was then thought to be the strongest and brightest explosions in the universe.
• A typical burst can produce as much energy as our sun will emit during its entire 10-billion-year existence.
• An odd characteristic is that it is not like a Big Bang, for the energy is focused into a narrow beam.
• For this reason, even though one a day is spotted, it is surmised that something like 500 are occurring daily.
• 
  These can cause an extinction event for Planet Earth, with one possibility the stripping away of our protective ozone layer exposing life to deadly ultraviolet light.
• No burst has so far come from our Milky Way Galaxy.  However, the Ordovician extinction, which happened 450 million years ago, might have caused our ice age and originated in our neighborhood.
• 
  So how does the Cow compare with a supernova or GRB?
• A Cow is more powerful and brighter than a supernova.
• More powerful than a hypernova?  Yes, because FBOTs can be 100 times brighter than a supernova.  Remember, the Cow and an FBOT are the same type of explosion.

• 
  What is an FBOT?
• Some theories, but no consensus answer.
• Maybe an Earth-size white dwarf star being ripped apart by the gravitational influence of a black hole between 100,000 to one million times the mass of our sun.
• Or, like the creation of a black hole or discharge of a gamma-ray burst, this could have something to do with the collapse of massive stars.
• A Northwestern University team has a cocoon theory.
• But there is a difference between a GRB and a Cow because the latter contains traces of hydrogen.

Enough of space science.  I'll end today with some music:

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