In a new record for the farthest measurement yet achieved (10 billion light years away), astronomers have now used the Webb Space Telescope obtain a reasonably accurate measurement of the mass of supermassive black hole in the early universe, estimated to be six billion times the mass of our Sun.

The stars orbiting Sag A* at the center of our own
galaxy, the Milky Way. Click for original image.

The black hole’s mass is about 6 billion times that of the sun, and is being observed at a time when the universe was only about 3 billion years old, about a quarter of its current age, offering unprecedented details into black holes in the early universe.

To find this, the team used data from NASA’s James Webb Space Telescope to track the motion of stars orbiting around the otherwise invisible black hole to measure its mass. Though the technique – known as stellar dynamics – has been used to measure dormant black holes in galaxies much closer to Earth, this is the first time it has been used to weigh one located such a great (cosmological) distance away.

For comparison, the Milky Way’s central super-massive black hole, Sagittarius A* (pronounced “A-star”), has been estimated at four million solar masses, using this same technique. The graphic to the right shows the various stars orbiting Sagittarius A* that have been tracked now for several decades in the infrared. As their orbits are refined, astronomers can use those orbits to determine the mass of the central object.

The scientists have now been able to do the same with this galaxy ten billion light years away. These observations however are certainly preliminary, and will be refined in the coming decades as more data is obtained.