Black holes are known for sucking matter in, not for sending it back out again. But in a universe first, two 'belches' have been found coming from a supermassive black hole.
The two burps, which occurred across a time span of 100,000 years, appear to show black holes go through cycles of feasting on matter around them, belching out particles, then going into a period of rest before starting up again.
"Black holes are voracious eaters, but it turns out they don't have very good table manners," Julie Comerford, from the University of Colorado, told the 231st American Astronomical Society meeting in Washington DC.
"There are a lot of examples of black holes with single burps emanating out, but we discovered a galaxy with a supermassive black hole that has not one but two burps."
The two burps were spotted coming from a black hole 800 million light years away by the Hubble and Chandra telescopes.
Almost all large galaxies have a supermassive black hole at the centre.
Emanating from the black hole at the centre of the galaxy rather clinically named SDSS J1354+1327, astronomers could see a cloud of blue-green gas - the remnants of a gassy burp. Over time, it had stretched 30,000 light years from the black hole.
But they were surprised when they found signs of a second belch 3000 light years from the galactic centre.
Researchers estimate the two burps occurred 100,000 years apart.
Dr Comerford said it's like someone burping after an appetiser course, then continuing onto the main and letting out a new burp.
Researchers believe the black hole burped twice because it's feasted twice on two separate galaxies.
"There's a stream of stars and gas connecting these two galaxies. That collision led gas to stream towards the supermassive black hole and feed it two separate meals that led to these two separate burps," said Dr Comerford.