It’s a tale as old as time: In the far reaches of the universe, a supercompact galaxy is, paradoxically, home to a supermassive black hole. In fact, galaxy M60-UCD1 is the smallest known galaxy to contain a black hole of such mass, leading scientists to believe that supermassive black holes may be more common than previously thought. The research was lead by the University of Utah.

The explanation? The dwarf galaxy didn’t start off so small, but gradually shrank as collisions with other galaxies stripped it of its stars.

“We don’t know of any other way you could make a black hole so big in an object this small,” says lead author Anil Seth, an assistant professor of physics and astronomy at the University of Utah. “There are a lot of similar ultracompact dwarf galaxies, and together they may contain as many supermassive black holes as there are at the centers of normal galaxies.”

To qualify as “supermassive,” a black hole must have a mass of at least one million times our Sun. The black hole at the center of the Milky way has the mas of four million Suns, yet only accounts for 0.01% of our galaxy’s total mass. The hole at the center of M60-UCD1, on the other hand, has the mas of 21 million Suns and accounts for a stunning 15% of the tiny galaxy’s total mass. How this is even possible has researchers scratching their heads.

“We believe this once was a very big galaxy with maybe 10 billion stars in it, but then it passed very close to the center of an even larger galaxy, M60, and in that process all the stars and dark matter in the outer part of the galaxy got torn away and became part of M60,” he says. “That was maybe as much as 10 billion years ago. We don’t know.”

M60-UCD1’s days may be numbered. M60, the larger galaxy it orbits, may eventually absorb it into it’s black hole, which has a mind-boggling mass of 4.5 billion suns. If and when that happens, the dwarf galaxy’s black hole will merge with the giant at the center of M60.