There might be a secret massive black hole in our galaxy that scientists didn’t know about till now!

In the cosmic detective agency, there's a new case that’s got astrophysicists buzzing: the possible existence of a hidden, massive black hole right in our galactic backyard. Like finding a giant squid in your swimming pool, this discovery hints at a black hole at least 8,200 times the mass of our Sun. If confirmed, it would be the second-largest black hole known in our Milky Way.

Hidden in plain darkness

Astrophysicist Maximilian Häberle and his team at the Max Planck Institute for Astronomy stumbled upon this potential black hole while examining over 500 images of Omega Centauri, a dense star cluster 18,000 light years away. These images, primarily used to calibrate Hubble’s instruments, inadvertently captured the movements of more than 1,50,000 stars.

While most stars behaved predictably, seven of them, situated near the cluster's centre, moved suspiciously fast — too fast to be explained by the cluster's gravity alone. This indicated the possible influence of a massive, unseen object: a black hole.

50,000 times the size of our Sun!

The rogue velocities of these stars suggest they are being gravitationally tugged by an object between 8,200 and 50,000 solar masses. If true, this would place the candidate black hole in the elusive intermediate-mass range, filling a significant gap between stellar-mass black holes (weighing as much as a single large star) and supermassive black holes like the one at our galaxy’s centre, Sagittarius A* (weighing 4.3 million solar masses).

Intermediate-mass black holes remain enigmatic, with their existence often debated. Some past candidates for these "middleweight" black holes turned out to be neutron stars instead. However, a confirmed detection would bridge our understanding of how black holes grow, possibly suggesting a stepwise process from stellar-mass to supermassive giants.

Firing up the JWST

Häberle and his team aren’t resting on their laurels. They plan to use the James Webb Space Telescope for follow-up observations. Unlike Hubble, which shows star movements in two dimensions, Webb will help map their velocities in 3D, offering a clearer picture and hopefully more definitive evidence of the black hole’s existence.

This cosmic detective story is far from over. As we push the boundaries of our telescopic capabilities, the possibility of uncovering new celestial phenomena keeps the universe as tantalising and mysterious as ever. Whether this candidate in Omega Centauri proves to be a true intermediate-mass black hole or another false alarm, the hunt itself drives our understanding of the cosmos to new heights

The findings of this research have been published in many journals, including Nature and Astronomy & Astrophysics.