One of astronomy's most astonishing recent discoveries is a supermassive black hole (SMBH) named Sagittarius A* at the centre of our Galaxy, with a mass exceeding one million times that of our Sun. Astronomers have since revealed that SMBHs inhabit the cores of many more distant galaxies, suggesting that a SMBH resides at the heart of almost every galaxy in the Universe.
To study these enigmatic objects,