Milky Way black hole appears to be hungry

The supermassive black hole at the center of the Milky Way galaxy is suddenly gorging on interstellar snacks, according to researchers, who can’t explain why it’s suddenly so hungry.

“We have never seen anything like this in the 24 years we have studied the supermassive black hole,” said UCLA professor Andrea Ghez, co-senior author of the study, published in Astrophysical Journal Letters. “It’s usually a pretty quiet, wimpy black hole on a diet. We don’t know what is driving this big feast.”

Black holes enjoy meals of cosmic dust and gas, sometimes stolen from stars. Their seemingly limitless consumption of space matter causes an immense amount of energy (radiation) to be emitted from the vortex, which gives the black hole its signature ring of light.

On May 13, the team of researchers discovered that the glowing area around the black hole’s event horizon — the “point of no return” — was suddenly shining twice as bright. Ghez calls the finding “unprecedented,” and scientists question whether the phenomenon marks a singular event or the beginning of a new phase for the galactic behemoth.

“The big question is whether the black hole is entering a new phase — for example, if the spigot has been turned up and the rate of gas falling down the black hole ‘drain’ has increased for an extended period — or whether we have just seen the fireworks from a few unusual blobs of gas falling in,” said UCLA professor and co-senior author Mark Morris.

Our nearest black hole, called Sagittarius A* or Sgr A*, was so unusually bright that lead author Tuan Do initially mistook it for nearby star S0-2. They now hypothesize that the sudden burst of brightness may have been caused by S0-2’s recent brush with the celestial vacuum in 2018. A similar theory involving an interstellar object known as G2, thought to be two stars stuck together, may have similarly been stripped of star matter during a run-in with Sgr A* in 2014.

Morris adds that the rare pyrotechnics may also have been just a few tasty asteroid morsels that crossed paths with Sgr A*.

Researchers assure that our nearest black hole is still not hungry enough to threaten humanity. At some 26,000 light years away, Do says the light they observed would have to be 10 billion times brighter to impact life on Earth.

Earlier this summer, the same UCLA team showed how the recent interactions between S0-2 and the black hole support Albert Einstein’s 1915 theory of general relativity.