Types of Holes
Messier 82 (M82), also known as the Cigar Galaxy, is an edge-on starburst galaxy located in the constellation Ursa Major. The galaxy lies at a distance of 11.4 to 12.4 million light years from Earth and has an apparent magnitude of 8.41. It has the designation NGC 3034 in the New General Catalogue.
GCIRS 13E is an infrared and radio object near the galactic centre. It is believed to be a cluster of hot massive stars, possibly containing an intermediate-mass black hole (IMBH) at its centre. GCIRS 13E was first identified as GCIRS 13, which was later resolved into two components GCIRS13E and W. GCIRS 13E was initially modelled as a single object, possibly a binary system.
Hyper-Luminous X-ray source 1, commonly known as HLX-1, is an intermediate-mass black hole candidate located in the galaxy ESO 243-49.
A black hole candidate known as M82 X-1 appears to have a mass of about 400 suns, making it one of only half a dozen suspected midsize black holes. Astronomers have used archival data from from an X-ray satellite to identify what they now believe is an unusual midsize black hole.
Messier 110, also known as NGC 205, is a dwarf elliptical galaxy that is a satellite of the Andromeda Galaxy. M110 contains some dust and hints of recent star formation, which is unusual for dwarf elliptical galaxies in general.
Messier 15 or M15 (also designated NGC 7078) is a globular cluster in the constellation Pegasus. It was discovered by Jean-Dominique Maraldi in 1746 and included in Charles Messier's catalogue of comet-like objects in 1764. At an estimated 12.0 billion years old, it is one of the oldest known globular clusters.
The new black hole candidate, NGC 1313 X-1, belongs to this rare class and has an estimated mass of 5,000 times that of our Sun. It lies in NGC 1313, a spiral galaxy located approximately 13.5 million light-years away in the direction of the constellation Reticulum.