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Very massive stars can undergo core collapse when nuclear fusion becomes unable to sustain the core against its own gravity; passing this threshold is the cause of all types of supernova except type Ia. The collapse may cause violent expulsion of the outer layers of the star resulting in a supernova.
A Type II supernova or SNII [1] (plural: supernovae) results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun ( M ☉ ) to undergo this type of explosion. [ 2 ]
Failed supernovae are thought to create stellar black holes by the collapsing of a red supergiant star in the early stages of a supernova. When the star can no longer support itself, the core collapses completely, forming a stellar-mass black hole, and consuming the nascent supernova without having the massive explosion.
The Type Ib supernova SN 2008D [1] [2] in galaxy NGC 2770, shown in X-ray (left) and visible light (right), at the corresponding positions of the images. (NASA image.) [3]Type Ib and Type Ic supernovae are categories of supernovae that are caused by the stellar core collapse of massive stars.
Because the core-collapse mechanism of a supernova is, at present, only partially understood, it is still not known whether it is possible for a star to collapse directly to a black hole without producing a visible supernova, or whether some supernovae initially form unstable neutron stars which then collapse into black holes; the exact ...
When core collapse occurs in a star with a core at least around fifteen times the Sun's mass (M ☉) — though chemical composition and rotational rate are also significant — the explosion energy is insufficient to expel the outer layers of the star, and it will collapse into a black hole without producing a visible supernova outburst.
The collapse produces two reactions: one breaks apart iron nuclei into 13 helium atoms and 4 neutrons, absorbing energy; and the second produces a wave of neutrinos that form a shock wave. While all models agree there is a convective shock, there is disagreement as to how important that shock is to the supernova explosion.
Gravitational collapse of a massive star, resulting in a Type II supernova. Gravitational collapse is the contraction of an astronomical object due to the influence of its own gravity, which tends to draw matter inward toward the center of gravity. [1] Gravitational collapse is a fundamental mechanism for structure formation in the universe.