The supermassive black hole at the centre of the Milky Way is putting on a light show NASA, ESA, and Hubble Heritage Team (STScI/AURA, Acknowledgment: T. Do, A.Ghez (UCLA), V. Bajaj (STScI)

The supermassive black hole at the heart of our galaxy has suddenly started flashing brighter than we have ever seen it, and astronomers don’t know why.

In the space of two hours, the black hole’s brightness changed 75-fold – and astronomers believe it was even brighter before this observation began. This is the brightest and most variable that the black hole, Sagittarius A*, has been since scientists first started studying it more than 20 …