https://www.cnet.com/news/scientists-confirm-theres-a-supermassive-black-hole-at-the-centre-of-our-galaxy/

This visualisation uses data from simulations of orbital motions of gas swirling around at about 30 percent of the speed of light on a circular orbit around the black hole.

According to a statement from ESO, a "consortium" of scientists from multiple European institutions observed flares of radiation coming from Sagittarius A, the massive object at the centre of our galaxy. Scientists have long assumed that Sagittarius A was a black hole, but this confirms it.