Ultraluminous x-ray sources (ULX) were first observed in 1980 by the Einstein Observatory and according to scientific surveys there is one ULX per galaxy, however, most galaxies do not have ULXs. Scientists still have not established the basic nature of these sources.
Russian scientists have studied in detail the source of a mysterious ultraluminous x-ray in a faraway galaxy, according to a research paper that was published on the arXiv.org website on 20 November. ULXs are astronomical sources of X-rays that are known for their luminosity, which exceeds that of neutron stars and stellar black holes.
The ULX in question is situated in the galaxy UGC 6456 14.8 million light years away and the scientific team led by Alexander Vinokurov from the Special Astrophysical Observatory identified the optical counterpart of this ULX. According to their research, it exhibits high optical and X-ray variability, however, the nature of such behaviour is uncertain and requires additional study. The absolute magnitude of this ULX in its luminescent state exceeds -7.6 making it one of the brightest ULXs in the optical range among known sources.
Despite scientists having conducted numerous studies of ultraluminous x-ray sources, their basic nature still remains a mystery.