Image: JPL-Caltech / NASA / EPA

Finnish researchers say they've discovered a new type of black hole.

Up until now, it has been assumed that the collapse of a massive star generally forms a massive black hole or a small neutron star. The mass gap between neutron stars and stellar mass black holes is a question that has been a matter of inquiry for numerous research teams.

The object now discovered and designated SWIFT J1753.5-0127 has a mass somewhere between that of a conventionally-recognized black hole and a neutron star. Previously, observed neutron stars have been found to have less than two solar masses, while black holes have over five.

Observations related to this new type of low-mass black hole were published in a paper by a group of reseachers at the University of Oulu, the University of Turku, the National Autonomous University of Mexico and an amateur astronomer from the USA, and published by the Monthly Notices of the Royal Astronomical Society.