Scientist found most massive stellar black hole in our galaxy

Astronomers have made an extraordinary discovery using the Very Large Telescope (VLT) of the European Southern Observatory (ESO). They have identified a quasar that is not only incredibly bright but also holds the record for being the most luminous object ever observed.

Astronomers have found the most massive stellar black hole in our galaxy, thanks to the wobbling motion it induces on a companion star. This artist’s impression shows the orbits of both the star and the black hole, dubbed Gaia BH3, around their common centre of mass. This wobbling was measured over several years with the European Space Agency’s Gaia mission. Additional data from other telescopes, including ESO’s Very Large Telescope in Chile, confirmed that the mass of this black hole is 33 times that of our Sun. The chemical composition of the companion star suggests that the black hole was formed after the collapse of a massive star with very few heavy elements, or metals, as predicted by theory.  Credit: ESO/L. Calçada

Quasars, the intensely bright centers of distant galaxies, are powered by supermassive black holes. The black hole at the heart of this particular quasar is expanding at an unprecedented rate, equivalent to the mass of our Sun every day. This makes it the fastest-growing black hole known to date.

The process by which black holes, such as the one powering this quasar, accumulate matter from their surroundings is so energetic that it emits vast amounts of light. This makes quasars some of the most radiant objects in our universe, so much so that even those located at great distances are visible from Earth.

Generally, the most luminous quasars indicate the presence of the fastest-growing supermassive black holes. “This black hole is growing at an unprecedented rate, with a mass of 17 billion Suns and consuming just over a Sun per day. This makes it the most radiant object in the known Universe,” says Christian Wolf, an astronomer at the Australian National University (ANU) and the lead author of the study.

This artist’s impression compares side-by-side three stellar black holes in our galaxy: Gaia BH1, Cygnus X-1 and Gaia BH3, whose masses are 10, 21 and 33 times that of the Sun respectively. Gaia BH3 is the most massive stellar black hole found to date in the Milky Way. The radii of the black holes are directly proportional to their masses, but note that the black holes themselves have not been directly imaged. Credit: ESO/M. Kornmesser