A collapsar (a

portmanteau In linguistics, a blend—also known as a blend word, lexical blend, or portmanteau—is a word formed by combining the meanings, and parts of the sounds, of two or more words together.

word formed by "collapsed" + "star") is a

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

which has undergone gravitational collapse. When a star no longer has enough fuel for significant fusion reactions, there are three possible outcomes, depending on the remnant star's mass: If it is less than the

Chandrasekhar limit The Chandrasekhar limit () is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about (). The limit was named after Subrahmanyan Chandrasekhar. White dwarfs resist gravitational collapse pr ...

(1.4 solar masses), the star will stabilize and shrink, becoming a

white dwarf A white dwarf is a Compact star, stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very density, dense: in an Earth sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place i ...

; between the Chandrasekhar limit and the

Tolman–Oppenheimer–Volkoff limit The Tolman–Oppenheimer–Volkoff limit (or TOV limit) is an upper bound to the mass of cold, non-rotating neutron stars, analogous to the Chandrasekhar limit for white dwarf stars. Stars more massive than the TOV limit collapse into a black hol ...

(approximately ), it will become a

neutron star A neutron star is the gravitationally collapsed Stellar core, core of a massive supergiant star. It results from the supernova explosion of a stellar evolution#Massive star, massive star—combined with gravitational collapse—that compresses ...

; and above the Tolman–Oppenheimer–Volkoff limit, the star will become a

black hole A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. Th ...

. However, it is theorized that the high density of neutron star cores allow for

quark matter Quark matter or QCD matter ( quantum chromodynamic) refers to any of a number of hypothetical phases of matter whose degrees of freedom include quarks and gluons, of which the prominent example is quark-gluon plasma. Several series of conferences ...

and, as a result, a star that is more massive than even the Tolman–Oppenheimer–Volkoff limit, yet still is not a black hole.

References

Neutron stars White dwarfs Black holes {{stellar-astronomy-stub

See also

References