Black Hole
A black hole is an astronomical object whose gravity is so strong that nothing—even light—can escape from within its event horizon. It forms when a massive star’s core collapses or through other processes, and may have an accretion disk of infalling matter that emits radiation. Supermassive black holes at galaxy centers influence stellar orbits, and mergers produce gravitational waves.
Source: nasa.gov
APODs including "Black Hole"
The COMPTEL Gamma-Ray Sky
29/05/1996
This premier gamma-ray view of the sky was produced by the COMPTEL instrument onboard NASA's orbiting Compton Gamma Ray Observatory. The entire sky is seen projected on a coordinate system centered on our Milky Way Galaxy with the plane of the Galaxy running across the middle of the picture. Gamma-ray intensity is represented by a false color map - low (blue) to high (white). COMPTEL's sensitivity to gamma-rays which have over 1 million times the energy of visible light photons reveals the locations of some of the Galaxy's most exotic objects. The brightest source, the Crab pulsar, is located near the plane of the Galaxy on the far right. Moving along the plane from the Crab, more than halfway toward the galactic center, another bright gamma-ray source, the Vela pulsar, appears. The galactic center itself, along with the famous black hole candidate Cygnus X-1 (near the plane, halfway from the center to the left edge) are also seen as bright sources. Both above and below the plane, spots of gamma-ray emission due to distant active galaxies are also visible.