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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.
The free-fall time is the characteristic time that would take a body to collapse under its own gravitational attraction, if no other forces existed to oppose the collapse.. As such, it plays a fundamental role in setting the timescale for a wide variety of astrophysical processes—from star formation to helioseismology to supernovae—in which gravity plays a dominant ro
The angular momentum of a stellar black hole is due to the conservation of angular momentum of the star or objects that produced it. The gravitational collapse of a star is a natural process that can produce a black hole. It is inevitable at the end of the life of a massive star when all stellar energy sources are exhausted.
A different reaction mechanism, photodisintegration, follows the initial pair-instability collapse in stars of at least 250 solar masses. This endothermic (energy-absorbing) reaction absorbs the excess energy from the earlier stages before the runaway fusion can cause a hypernova explosion; the star then collapses completely into a black hole. [5]
At the same time, gravity will attempt to contract the system even further, and will do so on a free-fall time = / /, where is the universal gravitational constant, is the gas density within the region, and = / is the gas number density for mean mass per particle (μ = 3.9 × 10 −24 g is appropriate for molecular hydrogen with 20% helium by ...
In the local (primarily thin) disk of the Milky Way, there appears to be no evidence of a strong AMR. [12] A sample of 229 nearby "thick" disk stars has been used to investigate the existence of an age-metallicity relation in the Galactic thick disk and indicates that there is an age-metallicity relation present in the thick disk.
Experts say the best auroras are usually within an hour or two of midnight (between 10 p.m. and 2 a.m. local time). These hours expand towards evening and morning as the level of geomagnetic ...
Shock waves in stellar environments, such as shocks inside a core collapse supernova explosion often become radiation mediated shocks. Such shocks are formed by photons colliding with the electrons of the matter, and the downstream of these shocks is dominated by radiation energy density rather than thermal energy of matter.