Material surrounding the black hole Sagittarius A*

This series of three images shows an artist’s impression of a bright “blob” of gas in the disc of material surrounding the black hole in the centre of our Galaxy, Sagittarius A*. This blob of material is responsible for the flares detected by the researchers. As the blob orbits the black hole, it is stretched out, and this expansion over time causes the delay between flares being detected at near-infrared wavelengths (with the VLT) and at submillimetre wavelengths (with APEX).