The Milky Way’s Black Hole Is Quiet Now, But Its Recent Past Was Far More Active

This image shows the region around the Milky Way's galactic center, with the SMBH Sagittarius A star and several gas clouds labelled. Astronomers observed the gas cloud G0.11-0.11 in greater detail than ever, and its x-ray emissions show that Sagittarius A star was very active in the recent past. Image Credit: Mori et al. 2015

The supermassive black hole in the Milky Way's galactic center, Sagittarius A-star, is known for being quiet and dim. But that wasn't always the case. The powerful XRISM x-ray telescope shows that it flared brightly at least once in the very recent past.

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