A0620-00 is a binary star

Binary star

A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...

 and black hole candidate

Black hole

A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...

 in the constellation of Monoceros

Monoceros

Monoceros is a faint constellation on the celestial equator. Its name is Greek for unicorn. Its definition is attributed to the 17th-century Dutch cartographer Petrus Plancius. It is bordered by Orion to the west, Gemini to the north, Canis Major to the south and Hydra to the east...

.

Evidence from observation

A0620-00 is a binary system consisting of a black hole with a mass roughly estimated to be 11.0±1.9 times the mass of Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

 and a K-type star similar to sun with mass of approximately 1.5 solar masses.

One of the stellar-structures in the A0620-00 binary-system is known to be a large dark compact stellar-structure,this between three to five times the mass of the sun.the other structure is observed to be a normal-range star(approximately one half the mass of sun).

significance

This binary-system is located at a distance of approximately 3,000 light years making the system the likely nearest possible place for a neighbouring black-hole.