A Tour of GSN 069

Narrator (April Jubett, CXC): There's an adage that it's not healthy to skip meals. Apparently, a supermassive black hole in the center of a galaxy millions of light years away has gotten the message.

A team of astronomers found X-ray bursts repeating about every nine hours originating from the center of a galaxy called GSN 069. Obtained with NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton, these data indicate that the supermassive black hole located there is consuming large amounts of material on a regular schedule.

While scientists had previously found two "stellar-mass" black holes (those that weigh about 10 times the Sun's mass) occasionally undergoing regular outbursts before, this behavior has never been detected from a supermassive black hole until now.

The black hole at the center of GSN 069, located 250 million light years from Earth, contains about 400,000 times the mass of the Sun. The researchers estimate that the black hole is consuming about four Moons' worth of material about three times a day. That's equivalent to almost a million billion billion pounds going into the black hole per feeding.

ESA's XMM-Newton was the first to observe this phenomenon in GSN 069 with the detection of two bursts on December 24, 2018. Astronomers then followed up with more XMM-Newton observations on January 16 and 17, 2019, and found five outbursts. Observations by Chandra less than a month later, on February 14 and 15, revealed an additional three outbursts.

The Chandra data were crucial for this study because they were able to show that the X-ray source is located in the center of the host galaxy, which is where a supermassive black hole is expected to be. The combination of data from Chandra and XMM-Newton implies that the size and duration of the black hole's meals have decreased slightly, and the gap between the meals has increased. Astronomers are planning future observations that will be crucial to see if the trend continues.