Black hole wakes after decades-long nap

A giant black hole has suddenly come to life in a flurry of X-ray flashes

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Black holes are often thought to be hungry giants eating as much matter as they can. But one black hole has left astronomers puzzled. After a nap that lasted decades, Ansky, the black hole at the centre of the SDSS1335+0728 galaxy, has burst back to life in dizzying style.