We've all woken up in a terrible mood from time to time, but a newly observed monster black hole is really having a bad day.

The previously inactive supermassive black hole at the heart of the galaxy SDSS1335+0728, located about 300 million light-years away from us, was seen erupting with the longest and most powerful X-ray blasts ever seen from such a cosmic titan.

This active phase marks the start of the supermassive black hole devouring matter around it and erupting with short-lived flaring events called quasiperiodic eruptions (QPEs).