“Mind-Blowing” Hot Gas Bubble Detected Zipping Around the Milky Way’s Supermassive


Hot Gas Bubble Swirling Around Our Supermassive Black Hole

Astronomers have spotted signs of a ‘hot spot’ orbiting Sagittarius A*, the black hole at the center of our galaxy.

Astronomers have spotted signs of a ‘hot spot’ orbiting Sagittarius A*, the

The Orbit of the Hot Spot Around Sagittarius A*

This shows a still image of the supermassive black hole Sagittarius A*, as seen by the Event Horizon Collaboration (EHT), with an artist’s illustration indicating where the modeling of the ALMA data predicts the hot spot to be and its orbit around the black hole. Credit: EHT Collaboration, ESO/M. Kornmesser (Acknowledgment: M. Wielgus)

The observations were made with ALMA in the Chilean Andes, during a campaign by the Event Horizon Telescope (EHT) Collaboration to image black holes. ALMA is — a radio telescope co-owned by the European Southern Observatory (ESO). In April 2017 the EHT linked together eight existing radio telescopes worldwide, including ALMA, resulting in the recently released first-ever image of Sagittarius A*. To calibrate the EHT data, Wielgus and his colleagues, who are members of the EHT Collaboration, used ALMA data recorded simultaneously with the EHT observations of Sagittarius A*. To the research team’s surprise, there were more clues to the nature of the black hole hidden in the ALMA-only measurements.


Using ALMA, astronomers have found a hot bubble of gas that swirls around Sagittarius A*, the black hole at the center of our galaxy, at 30% of the speed of light.

By chance, some of the observations were done shortly after a burst or flare of X-ray energy was emitted from the center of our galaxy, which was spotted by
This video shows an animation of a hot spot, a bubble of hot gas, in orbit around Sagittarius A*, a black hole four million times more massive than our Sun that resides at the center of our “Mind-Blowing” Hot Gas Bubble Detected Zipping Around the Milky Way’s Supermassive