Search results
Results from the WOW.Com Content Network
The Kerr metric or Kerr geometry describes the geometry of empty spacetime around a rotating uncharged axially symmetric black hole with a quasispherical event horizon.The Kerr metric is an exact solution of the Einstein field equations of general relativity; these equations are highly non-linear, which makes exact solutions very difficult to find.
NICER detected X-ray light from a recently discovered black hole, called MAXI J1820+070 (J1820 for short), as it consumed material from a companion star. Waves of X-rays formed "light echoes" that reflected off the swirling gas near the black hole and revealed changes in the environment’s size and shape.
Sagittarius A*, abbreviated as Sgr A* (/ ˈ s æ dʒ ˈ eɪ s t ɑːr / SADGE-AY-star [3]), is the supermassive black hole [4] [5] [6] at the Galactic Center of the Milky Way.Viewed from Earth, it is located near the border of the constellations Sagittarius and Scorpius, about 5.6° south of the ecliptic, [7] visually close to the Butterfly Cluster (M6) and Lambda Scorpii.
A rotating black hole is a black hole that possesses angular momentum. In particular, it rotates about one of its axes of symmetry. All celestial objects – planets, stars , galaxies, black holes – spin. [1] [2] [3] The boundaries of a Kerr black hole relevant to astrophysics. Note that there are no physical "surfaces" as such.
A black hole with the mass of a car would have a diameter of about 10 −24 m and take a nanosecond to evaporate, during which time it would briefly have a luminosity of more than 200 times that of the Sun. Lower-mass black holes are expected to evaporate even faster; for example, a black hole of mass 1 TeV/c 2 would take less than 10 −88 ...
Another study from June of 2023 reported an X-ray echo that pointed to the idea that the Milky Way’s black hole, Sagittarius A* (Sgr A*), had experienced its own flare up some 200 years ago.
However, in the case of long time evolution or continuous quantum emission, the process is off-equilibrium and is characterised by an initial state dependent black hole mass or temperature vs. time curve. The observers far away can retrieve the information stored in the initial black hole from this mass or temperature versus time curve.
Fig 4–2. Relativistic time dilation, as depicted in a single Loedel spacetime diagram. Both observers consider the clock of the other as running slower. Relativistic time dilation refers to the fact that a clock (indicating its proper time in its rest frame) that moves relative to an observer is observed to run slower. The situation is ...