OGLE-2011-BLG-0462, also known as MOA-2011-BLG-191, is a stellar-mass

black hole A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts t ...

isolated in

interstellar space Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, predo ...

. OGLE-2011-BLG-0462 lies at a distance of 5,000 light years in the direction of the

galactic bulge In astronomy, a galactic bulge (or simply bulge) is a tightly packed group of stars within a larger star formation. The term almost exclusively refers to the central group of stars found in most spiral galaxies (see galactic spheroid). Bulges w ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Sagittarius. The black hole has a mass between 1.6 and , but might weigh as much as The discovery of OGLE-2011-BLG-0462 makes this object the first truly isolated black hole found. OGLE-2011-BLG-0462 was discovered through

microlensing Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronomers ...

when it passed in front of a background star that was 20,000 light years away from Earth. The black hole's gravity bent the star's light, causing a sharp spike in brightness that was detected by the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

. It took six years to confirm the existence of OGLE-2011-BLG-0462. Its initial kick velocity has been estimated to have an upper limit of

100\ kms^

Reference

Black holes Sagittarius (constellation) Gravitational lensing {{astronomy-stub

See also

Reference