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In equations, Hawking showed that if one denotes the creation and annihilation operators at a frequency for a quantum field propagating in the black-hole background by and † then the expectation value of the product of these operators in the state formed by the collapse of a black hole would satisfy † = / where k is the Boltzmann constant ...
A 2010 paper suggested that the black hole may be displaced from the galactic center by about seven parsecs (23 light-years). [79] This was claimed to be in the opposite direction of the known jet, indicating acceleration of the black hole by it. Another suggestion was that the offset occurred during the merger of two supermassive black holes.
Messier 78 or M78, also known as NGC 2068, is a reflection nebula in the constellation Orion. It was discovered by Pierre Méchain in 1780 and included by Charles Messier in his catalog of comet-like objects that same year. [4] M78 is the brightest diffuse reflection nebula of a group of nebulae that includes NGC 2064, NGC 2067 and NGC 2071.
A black hole of one solar mass (M ☉ = 2.0 × 10 30 kg) takes more than 10 67 years to evaporate—much longer than the current age of the universe at 1.4 × 10 10 years. [22] But for a black hole of 10 11 kg, the evaporation time is 2.6 × 10 9 years. This is why some astronomers are searching for signs of exploding primordial black holes.
(Supermassive black holes up to 21 billion (2.1 × 10 10) M ☉ have been detected, such as NGC 4889.) [17] Unlike stellar mass black holes, supermassive black holes have comparatively low average densities. (Note that a (non-rotating) black hole is a spherical region in space that surrounds the singularity at its center; it is not the ...
The first image of the black hole at the center of the Milky Way galaxy, named Sagittarius A*, has been captured by NASA's Event Horizon Telescope.
An animation of how light rays can be gravitationally bent to form a photon sphere. A photon sphere, or photon ring [1] or photon circle, [2] arises in a neighbourhood of the event horizon of a black hole where gravity is so strong that emitted photons will not just bend around the black hole but also return to the point where they were emitted from and consequently display boomerang-like ...
According to the Bekenstein bound, the entropy of a black hole is proportional to the number of Planck areas that it would take to cover the black hole's event horizon.. In physics, the Bekenstein bound (named after Jacob Bekenstein) is an upper limit on the thermodynamic entropy S, or Shannon entropy H, that can be contained within a given finite region of space which has a finite amount of ...