Additional observations concerning the superluminous supernova in 2015 suggest that the event from the distant galaxy was actually caused by a spinning black hole swallowing a star. The event was two times brighter than the previous record and 20 times brighter than the total light produced in the Milky Way.
The research was conducted by an international team. As part of the study, additional observations were made concerning the event that took place approximately 4 billion light-years from our planet.
Superluminous Supernova - Theory Dismissed
In 2015, the All Sky Automated Survey for SuperNovae (ASAS-SN) spotted an event, which they called ASASSN-15lh, recording the most luminous supernova that we had ever observed. The event consisted of the explosion of an extraordinarily massive star exploding at the end of its life.
"We observed the source for 10 months following the event and have concluded that the explanation is unlikely to lie with an extraordinarily bright supernova. Our results indicate that the event was probably caused by a rapidly spinning supermassive black hole as it destroyed a low-mass star," noted Giorgos Leloudas, lead author of the study.
The researchers observed and analyzed the event from a different range of telescopes located both on Earth and in space. Among those, Hubble Space Telescope was also involved in this study.
Kerr Black Hole - Explanation Of The Phenomenon
The data analyzed by the scientists suggests that three different stages of the event followed the initial observations. During the 10 months of follow-up monitoring, the researchers reached the conclusion that the event was — in fact — a tidal disruption and not a superluminous supernova.
The re-brightening of the ultraviolet light as well as the location of the occurrence — a huge, passive galaxy — suggests that the event is not a supernova, which would not usually occur in such environmental circumstances.
A Kerr black hole is one that spins so rapidly, that it makes any celestial corpus around it attracted to its effects, even when they are beyond the event horizon, the normal boundary beyond which celestial formations would normally not be attracted in the black hole.
In the case of this research, the total mass of the galaxy suggests that, at its turn, the black hole is giant as well, reaching a mass at more than 100 million times bigger that of the Sun. Even so, the black hole would only be able to attract a star beyond the event horizon if it were a Kerr black hole, one that spins very rapidly.
When the occurrence was first observed, the scientific world was fascinated by the discovery.
"We have to ask, how is that even possible? It takes a lot of energy to shine that bright, and that energy has to come from somewhere," noted astronomer Krzysztof Stanek with Ohio State University, a co-author of a study published in the journal Science in January 2016.
