I found this article quite illuminating:
QuoteIt first showed itself four years ago, when astronomers observed a bright burst of light coming from a tiny galaxy about 500 million light-years from Earth.
Now, they know it was a fast blue optical transient, captured in radio waves and X-rays. It produced one of the fastest outflows ever observed, blasting out gas and particles at more than 55% the speed of light.
The amount of material in the 2016 explosion was between one to 10% of the mass of our sun, and it represents a new type of explosion in the universe, according to a study published Tuesday in The Astrophysical Journal Letters.
These fast blue optical transients, or FBOTs, are hard to catch. They are quick, energetic and powerful explosions that fade away quickly.
Only three have been observed to since they were recognized in 2014, including this new one known as CSS161010. The explosions are so hot that they give off a blue glow. Their ephemeral glow and fading process is much quicker than a supernova, an increasingly bright star that explodes and ejects most of its mass before dying.
The most well-known of these three events belongs to AT2018COW, or "The Cow," a rare event detected in 2018 that was likely the birth of a black hole or neutron star. But the 2016 event was brighter, faster and heavier.
https://www.cnn.com/2020/05/26/world/fbot-transient-object-trnd-scn/index.html (https://www.cnn.com/2020/05/26/world/fbot-transient-object-trnd-scn/index.html)
Thank you for posting that,
Randy. :thumbsup:
The connection between the relative scarcity of heavier elements in small galaxies and the incidence of this new type of explosion/matter ejection is not explained in the article. Apparently the author of the article decided that it would be beyond the scope of the article to explore that question.
I found the hypothesized mechanism elsewhere:
QuoteThe amount of metals affects how much mass stars lose throughout their lifetimes in the form of stellar wind. A star without metals can potentially retain more of its mass, producing a bigger explosion at the end of its life.
[source (https://phys.org/news/2020-05-astrophysicists-capture-class-transient.html)]
Something I just learned from the article you posted, Recusant:
QuoteAstronomers use the word "metals" to include all materials except hydrogen and helium.
:thumbsup: I think I first learned that from one of Asimov's science books.