Astronomers at the University of Texas at Austin’s McDonald Observatory near Fort Davis have found what they believe may be the most massive black hole ever discovered, according to a report in the journal Nature.

Equal to the mass of 17 billion suns, this black hole sits at the center of galaxy NGC 1277 in the constellation Perseus. It's 220 million light years from Earth and four light days in diameter, meaning that it would take light four days to travel across it — not that light could, because it’s a black hole.

To put that size in perspective, Earth’s orbit is 17 light minutes in diameter, or .0029 percent of four light days. The black hole is large, to say the least. Even more impressive is that it accounts for 14 percent of its galaxy’s mass. The average is 0.1 percent.

Astronomers studied NGC 1277 with the Hobby-Eberly Telescope as part of their Massive Galaxy Survey to understand the relationship between galaxies, black holes and how they grow.

What makes this discovery even more interesting is that previously astronomers had found the largest black holes in large “blobby” galaxies called “ellipticals.” NGC 1277 is considerably smaller, at only one-tenth the size and mass of the Milky Way, and it is shaped more like a lens.

Team member Karl Gebhardt of UT Austin says this find might signify a discovery of a new galaxy.

“This is a really oddball galaxy,” he says. “It's almost all black hole. This could be the first object in a new class of galaxy-black hole systems.”

So far the team at McDonald Observatory have studied 700 of their 800 galaxies with the Hobby-Eberly Telescope, a 9.2 meter joint project between UT Austin; Penn State; Ludwig Maximilians Universität München in Munich, Germany; and Georg-August-Universität Göttingen in Germany.