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39-412: SBH can refer to: Stellar black hole or Supermassive black hole Gustaf III Airport , Saint Barthélemy, IATA code Sephardic Bikur Holim , a charity organisation Sequencing by hybridization , DNA sequencing method The Service Book and Hymnal of Lutheran churches Singapore Badminton Hall State Bank of Hyderabad Topics referred to by

78-406: A stellar black hole . A small mass has an extremely small Schwarzschild radius. A black hole of mass similar to that of Mount Everest would have a Schwarzschild radius much smaller than a nanometre . Its average density at that size would be so high that no known mechanism could form such extremely compact objects. Such black holes might possibly be formed in an early stage of the evolution of

117-407: A (non-rotating) black hole is a spherical region in space that surrounds the singularity at its center; it is not the singularity itself.) With that in mind, the average density of a supermassive black hole can be less than the density of water. The Schwarzschild radius of a body is proportional to its mass and therefore to its volume, assuming that the body has a constant mass-density. In contrast,

156-443: A black hole. A direct proof of the existence of a black hole would be if one actually observes the orbit of a particle (or a cloud of gas) that falls into the black hole. The large distances above the galactic plane achieved by some binaries are the result of black hole natal kicks. The velocity distribution of black hole natal kicks seems similar to that of neutron star kick velocities. One might have expected that it would be

195-538: A black hole. It is inevitable at the end of the life of a massive star when all stellar energy sources are exhausted. If the mass of the collapsing part of the star is below the Tolman–Oppenheimer–Volkoff (TOV) limit for neutron-degenerate matter , the end product is a compact star – either a white dwarf (for masses below the Chandrasekhar limit ) or a neutron star or a (hypothetical) quark star . If

234-452: A bright, rapidly rotating giant star in a binary system with an unseen companion emitting no light, including x-rays, but having a mass of 3.3 +2.8 −0.7 solar masses. This is interpreted to suggest that there may be many such low-mass black holes that are not currently consuming any material and are hence undetectable via the usual x-ray signature. The upper mass gap is predicted by comprehensive models of late-stage stellar evolution. It

273-556: A dozen solar masses . Candidates outside our galaxy come from gravitational wave detections: Candidates outside our galaxy from X-ray binaries: The disappearance of N6946-BH1 following a failed supernova in NGC 6946 may have resulted in the formation of a black hole. Schwarzschild radius The Schwarzschild radius is given as r s = 2 G M c 2 , {\displaystyle r_{\text{s}}={\frac {2GM}{c^{2}}},} where G

312-449: A high-mass supernova remnant; i.e., the lower bound of the upper mass gap may represent a mass cutoff. Observations of the LB-1 system of a star and unseen companion were initially interpreted in terms of a black hole with a mass of about 70 solar masses, which would be excluded by the upper mass gap. However, further investigations have weakened this claim. Black holes may also be found in

351-497: A mass below 3.0 solar masses; none of the compact systems with a mass above 3.0 solar masses display the properties of a neutron star. The combination of these facts makes it more and more likely that the class of compact stars with a mass above 3.0 solar masses are in fact black holes. Note that this proof of the existence of stellar black holes is not entirely observational but relies on theory: we can think of no other object for these massive compact systems in stellar binaries besides

390-426: A merger event of two smaller black holes. As of June 2020 , the binary system 2MASS J05215658+4359220 was reported to host the smallest-mass black hole currently known to science, with a mass 3.3 solar masses and a diameter of only 19.5 kilometers. There is observational evidence for two other types of black holes, which are much more massive than stellar black holes. They are intermediate-mass black holes (in

429-427: A partial collapse, which in turn causes greatly accelerated burning in a runaway thermonuclear explosion, resulting in the star being blown completely apart without leaving a stellar remnant behind. Pair-instability supernovae can only happen in stars with a mass range from around 130 to 250 solar masses ( M ☉ ) and low to moderate metallicity (low abundance of elements other than hydrogen and helium –

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468-510: A range from 1.5 to 3 solar masses. The maximum observed mass of neutron stars is about 2.14  M ☉ for PSR J0740+6620 discovered in September, 2019. In the theory of general relativity , a black hole could exist of any mass. The lower the mass, the higher the density of matter has to be in order to form a black hole. (See, for example, the discussion in Schwarzschild radius ,

507-649: A situation common in Population III stars ). However, this mass gap is expected to be extended down to about 45 solar masses by the process of pair-instability pulsational mass loss, before the occurrence of a "normal" supernova explosion and core collapse. In nonrotating stars the lower bound of the upper mass gap may be as high as 60 M ☉ . The possibility of direct collapse into black holes of stars with core mass > 133 M ☉ , requiring total stellar mass of > 260 M ☉ has been considered, but there may be little chance of observing such

546-509: A supermassive black hole. It is thought that supermassive black holes like these do not form immediately from the singular collapse of a cluster of stars. Instead they may begin life as smaller, stellar-sized black holes and grow larger by the accretion of matter, or even of other black holes. The Schwarzschild radius of the supermassive black hole at the Galactic Center of the Milky Way

585-428: A type of gamma ray burst . These black holes are also referred to as collapsars . By the no-hair theorem , a black hole can only have three fundamental properties: mass, electric charge, and angular momentum. 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

624-468: Is a spacetime singularity and cannot be removed. The Schwarzschild radius is nonetheless a physically relevant quantity, as noted above and below. This expression had previously been calculated, using Newtonian mechanics, as the radius of a spherically symmetric body at which the escape velocity was equal to the speed of light. It had been identified in the 18th century by John Michell and Pierre-Simon Laplace . The Schwarzschild radius of an object

663-552: Is another form of the Heisenberg uncertainty principle on the Planck scale . (See also Virtual black hole ). The Schwarzschild radius equation can be manipulated to yield an expression that gives the largest possible radius from an input density that doesn't form a black hole. Taking the input density as ρ , For example, the density of water is 1000 kg/m . This means the largest amount of water you can have without forming

702-456: Is approximately 12 million kilometres. Its mass is about 4.1 million  M ☉ . Stellar black holes have much greater average densities than supermassive black holes. If one accumulates matter at nuclear density (the density of the nucleus of an atom, about 10 kg/m ; neutron stars also reach this density), such an accumulation would fall within its own Schwarzschild radius at about 3  M ☉ and thus would be

741-500: Is defined as mass of a black hole divided by the volume of its Schwarzschild sphere. As the Schwarzschild radius is linearly related to mass, while the enclosed volume corresponds to the third power of the radius, small black holes are therefore much more dense than large ones. The volume enclosed in the event horizon of the most massive black holes has an average density lower than main sequence stars. A supermassive black hole (SMBH)

780-402: Is different from Wikidata All article disambiguation pages All disambiguation pages Stellar black hole A stellar black hole (or stellar-mass black hole ) is a black hole formed by the gravitational collapse of a star . They have masses ranging from about 5 to several tens of solar masses . They are the remnants of supernova explosions, which may be observed as

819-400: Is expected that with increasing mass, supermassive stars reach a stage where a pair-instability supernova occurs, during which pair production , the production of free electrons and positrons in the collision between atomic nuclei and energetic gamma rays , temporarily reduces the internal pressure supporting the star's core against gravitational collapse. This pressure drop leads to

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858-449: Is observable in X-rays, whereas the companion star can be observed with optical telescopes . The energy release for black holes and neutron stars are of the same order of magnitude. Black holes and neutron stars are therefore often difficult to distinguish. The derived masses come from observations of compact X-ray sources (combining X-ray and optical data). All identified neutron stars have

897-511: Is proportional to its mass. Accordingly, the Sun has a Schwarzschild radius of approximately 3.0 km (1.9 mi), whereas Earth 's is approximately 9 mm (0.35 in) and the Moon 's is approximately 0.1 mm (0.0039 in). The simplest way of deriving the Schwarzschild radius comes from the equality of the modulus of a spherical solid mass' rest energy with its gravitational energy: So,

936-641: Is suspected on the basis of a scarcity of observed candidates with masses within a few solar masses above the maximum possible neutron star mass. The existence and theoretical basis for this possible gap are uncertain. The situation may be complicated by the fact that any black holes found in this mass range may have been created via the merging of binary neutron star systems, rather than stellar collapse. The LIGO / Virgo collaboration has reported three candidate events among their gravitational wave observations in run O3 with component masses that fall in this lower mass gap. There has also been reported an observation of

975-933: Is the gravitational constant , M is the object mass, and c is the speed of light . In 1916, Karl Schwarzschild obtained the exact solution to Einstein's field equations for the gravitational field outside a non-rotating, spherically symmetric body with mass M {\displaystyle M} (see Schwarzschild metric ). The solution contained terms of the form 1 − r s / r {\displaystyle 1-{r_{\text{s}}}/r} and 1 1 − r s / r {\displaystyle {\frac {1}{1-{r_{\text{s}}}/r}}} , which becomes singular at r = 0 {\displaystyle r=0} and r = r s {\displaystyle r=r_{\text{s}}} respectively. The r s {\displaystyle r_{\text{s}}} has come to be known as

1014-414: Is the largest type of black hole, though there are few official criteria on how such an object is considered so, on the order of hundreds of thousands to billions of solar masses. (Supermassive black holes up to 21 billion (2.1 × 10 )  M ☉ have been detected, such as NGC 4889 .) Unlike stellar mass black holes , supermassive black holes have comparatively low average densities. (Note that

1053-873: The Compton wavelength ( 2 π ℏ / M c {\displaystyle 2\pi \hbar /Mc} ) corresponding to a given mass are similar when the mass is around one Planck mass ( M = ℏ c / G {\textstyle M={\sqrt {\hbar c/G}}} ), when both are of the same order as the Planck length ( ℏ G / c 3 {\textstyle {\sqrt {\hbar G/c^{3}}}} ). Thus, r s r ∼ ℓ P 2 {\displaystyle r_{s}r\sim \ell _{P}^{2}} or Δ r s Δ r ≥ ℓ P 2 {\displaystyle \Delta r_{s}\Delta r\geq \ell _{P}^{2}} , which

1092-396: The Schwarzschild radius . The physical significance of these singularities was debated for decades. It was found that the one at r = r s {\displaystyle r=r_{\text{s}}} is a coordinate singularity, meaning that it is an artifact of the particular system of coordinates that was used; while the one at r = 0 {\displaystyle r=0}

1131-505: The Schwarzschild radius reads as Any object whose radius is smaller than its Schwarzschild radius is called a black hole . The surface at the Schwarzschild radius acts as an event horizon in a non-rotating body (a rotating black hole operates slightly differently). Neither light nor particles can escape through this surface from the region inside, hence the name "black hole". Black holes can be classified based on their Schwarzschild radius, or equivalently, by their density, where density

1170-499: The center of globular clusters ) and supermassive black holes in the center of the Milky Way and other galaxies. Stellar black holes in close binary systems are observable when the matter is transferred from a companion star to the black hole; the energy released in the fall toward the compact star is so large that the matter heats up to temperatures of several hundred million degrees and radiates in X-rays . The black hole, therefore,

1209-501: The collapsing star has a mass exceeding the TOV limit, the crush will continue until zero volume is achieved and a black hole is formed around that point in space. The maximum mass that a neutron star can possess before further collapsing into a black hole is not fully understood. In 1939, it was estimated at 0.7 solar masses, called the TOV limit . In 1996, a different estimate put this upper mass in

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1248-422: The gravitational collapse of a star. These are sometimes distinguished as the "lower" and "upper" mass gaps, roughly representing the ranges of 2 to 5 and 50 to 150 solar masses ( M ☉ ), respectively. Another range given for the upper gap is 52 to 133 M ☉ . 150  M ☉ has been regarded as the upper mass limit for stars in the current era of the universe. A lower mass gap

1287-743: The gravitational radius in the form r s = 2 ( G / c 3 ) M c {\displaystyle r_{s}=2\,(G/c^{3})Mc} , (see also virtual black hole ). Gravitational time dilation near a large, slowly rotating, nearly spherical body, such as the Earth or Sun can be reasonably approximated as follows: t r t = 1 − r s r {\displaystyle {\frac {t_{r}}{t}}={\sqrt {1-{\frac {r_{\mathrm {s} }}{r}}}}} where: The Schwarzschild radius ( 2 G M / c 2 {\displaystyle 2GM/c^{2}} ) and

1326-497: The mass gap through mechanisms other than those involving a single star, such as the merger of black holes. Our Milky Way galaxy contains several stellar-mass black hole candidates (BHCs) which are closer to us than the supermassive black hole in the galactic center region. Most of these candidates are members of X-ray binary systems in which the compact object draws matter from its partner via an accretion disk. The probable black holes in these pairs range from three to more than

1365-403: The momenta that were the same with black holes receiving lower velocity than neutron stars due to their higher mass but that doesn't seem to be the case, which may be due to the fall-back of asymmetrically expelled matter increasing the momentum of the resulting black hole. It is predicted by some models of stellar evolution that black holes with masses in two ranges cannot be directly formed by

1404-490: The physical radius of the body is proportional to the cube root of its volume. Therefore, as the body accumulates matter at a given fixed density (in this example, 997 kg/m , the density of water), its Schwarzschild radius will increase more quickly than its physical radius. When a body of this density has grown to around 136 million solar masses (1.36 × 10   M ☉ ), its physical radius would be overtaken by its Schwarzschild radius, and thus it would form

1443-480: The radius of a black hole.) There are no known stellar processes that can produce black holes with mass less than a few times the mass of the Sun. If black holes that small exist, they are most likely primordial black holes . Until 2016, the largest known stellar black hole was 15.65 ± 1.45 solar masses. In September 2015, a rotating black hole of 62 ± 4 solar masses was discovered by gravitational waves as it formed in

1482-403: The same term [REDACTED] This disambiguation page lists articles associated with the title SBH . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=SBH&oldid=1036613671 " Category : Disambiguation pages Hidden categories: Short description

1521-470: The universe, just after the Big Bang , when densities of matter were extremely high. Therefore, these hypothetical miniature black holes are called primordial black holes . When moving to the Planck scale ℓ P = ( G / c 3 ) ℏ {\displaystyle \ell _{P}={\sqrt {(G/c^{3})\,\hbar }}} ≈ 10 m , it is convenient to write

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