In 1990 a large eruption was detected in the black hole located in the center of the galaxy IC3599, 280 million light years from Earth. Later, in 2010, a new eruption was detected. This type of phenomena They occur approximately once every 10,000 to 100,000 years per galaxy. It is extremely rare, so the eruption of the same black hole with just 20 years of separation was worth investigating. Therefore, a team of scientists from Northern Kentucky University decided to monitor the black hole to immediately capture any other eruptions that occurred in the future.
Those of 1990 and 2010 had been rebuilt a posterioribut in order to understand them they needed to capture them in real time. And they did it. It took 15 years, until on October 31, 2025, another one was captured. Without a doubt, it was a most exciting Halloween night.
What they captured. The authors of the study just published followed this black hole in three different ways. On the one hand, with the Neil Gehrels Swift telescope, specialized in detecting gamma ray emissions. He is currently not in his best days. It has been necessary launch a ship to rescue it before it falls out of orbit. However, so far it has done its job very well. These scientists also used the XMMNewton, a space observatory specialized in detecting X-ray emissions. And, finally, they took data using ground-based telescopes at the Lick, Xinglong and Caucasus Mountain observatories.
With all this, on October 31, 2025 was observed that the black hole’s brightness increased 50 times compared to its lowest levels. Something was happening. Another eruption had occurred in the black hole. But why?
The data to have everything clearer. To understand what was happening in the black hole it was necessary to have as much data as possible. Therefore, we began measuring its size. It can’t be done directly, but it can be done by analyzing the host-galaxy mass ratio. This allows the mass of the black hole to be extrapolated by analyzing the galaxy that contains it. Thus, they saw that the black hole is equivalent to 2 million solar masses. On the other hand, terrestrial telescopes analyzed its spectrum and detected a series of lines during the eruption that are not normally present. These were mostly related to highly ionized iron, so it seemed that the eruption consisted mostly of ionized gases released over a long distance.
The reasons for the black hole eruption. The eruption of a black hole is usually caused by the destruction of a star that came too close. It can also occur when two black holes orbit each other. However, all of these hypotheses did not fit with the data that was measured in IC3599. What seemed most fitting to these scientists was that it was an episode of instability in the radiation pressure of the accretion disk. This happens when light presses the gas in the inner disk so much that great instability is generated in this area, followed by its collapse. The ionized gas is ejected until the disc is empty. Afterwards, it is cooled and little by little it is slowly refilled.
It is a process that It does not have a fixed periodicity. Between the first and the second eruption 19.5 years passed and between this and the third 15.7 years. For this reason, the hypothesis that it is due to the action of stars or compact objects with a fixed orbit is also ruled out.
A fact that draws attention. Although the eruption of the black hole does not follow a fixed periodicity, there is something that does occur with a certain periodicity: an oscillation of X-ray measured every 7.4 hours. This may be something known as quasi-periodic oscillation, but at the moment it is not known what this is due to. It will be necessary to continue monitoring this black hole. 15 years have not been enough.
Image | Pixabay artistic rendering
GIPHY App Key not set. Please check settings