Talk:Collapsar

Definition
This is just wrong. A collapsar is not a hypernova. It is a gravitationally collapsed object such as a black hole. Simply because one model for producing a hypernova is called the collapsar model (because it produces and is driven by) a black hole, does not mean collapsar should redirect to hypernova. Lithopsian (talk) 15:39, 5 June 2012 (UTC)


 * Whatever collapsar may have meant in 2012, it now refers to a special type of supernova. A massive star's core collapses to form a black hole as the star's outer layers explode as a supernova. It requires that there be a disk of material around the newly formed black hole.  References are: from Science News (May 2019: https://www.sciencenews.org/article/dying-stars-called-collapsars-may-forge-much-universe-gold
 * and from the Astrophysical Journal (May 2019): https://arxiv.org/pdf/1905.04315.pdf . The collapsar model was first proposed by Stan Woosley in March 1993 in a paper in the Astrophysical Journal, https://articles.adsabs.harvard.edu/pdf/1993ApJ...405..273W . 24.11.1.26 (talk) 17:12, 19 July 2022 (UTC)

Is "collapsar" an insufficient name to describe different classes of stars?
One dictionary definition includes white dwarfs, neutron stars, and black holes as collapsars. In terms of defining reality, I think the name "collapsar" could be misleading or insufficient to describe different classes of stars. A white dwarf is much different then a neutron star or black hole. Proton collapse does not occur in a white dwarf but proton collapse probably is probably what happens in a black hole or neutron star >2SM. The term "proton collapsar" is probably a better name for the class of stars that includes black holes or neutron stars (>2 SM). 151.202.5.131 (talk) 18:16, 20 June 2016 (UTC)BG
 * Doesn't really matter what you'd like collapsar to mean. Doesn't really matter what I'd like it to mean.  If it is used to describe very different objects, then we have to explain that.  If it isn't, then the article should be adjusted accordingly.  I don't think it is really used for white dwarfs, but certainly sometimes for neutron stars. Lithopsian (talk) 20:08, 20 June 2016 (UTC)

Reply: The Webster dictionary does not define collapsar well, but according to the Oxford dictionary a collapsar is "an old star that has collapsed under its own gravity to form a white dwarf, neutron star, or black hole." So I will rephrase: My problem with this is a white dwarf is much different than a neutron star or black hole, the densities for example are way over a million times different.

Why not use the term "collapsar" with an acting verb to describe what collapses in a star smaller than about 2.0 Schwarzschild radius? Lets consider what happens if an attempt is made to compress a star of 2.0 Schwarzschild radius down to 1.0 Schwarzschild radius. Assuming the star is made of protons, neutrons, and electrons, this should be reflected in the name for the different types of collapse that could happen (unless all types of particles collapse at the same instant). Consider: (1) A "proton collapsar" (2) A "neutron collapsar" (3) An "electron collapsar".

(3) sounds like baloney. As for (2) a neutron is just a proton and an electron so this process is the same as (1). When you compress a star enough at somewhere below about 2.0 Schwarzschild radius, you should get proton collapse and I think thats what should be analyzed. "Proton collapsar" would be a good name to describe this family of stars. It does not include white dwarfs. Just using the plain name "collapsar" indicates little about what is collapsing.

I'm going to add some conventional information about collapsars. This info came from: http://planetfacts.org/collapsar/. Let me know if you have a problem with any of it or what can be improved. IMO to just use the term "collapsar" to describe the 3 types of stars that have run out of fusion fuel can/is somewhat misleading. Yes, "collapsar" is a definition. But has a neutron star or a white dwarf for example really "collapsed"? 72.69.60.186 (talk) 01:01, 25 June 2016 (UTC)BG

collapsar

 * Greek: καταρριμμένος αστέρας

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