NASA astronomers have just discovered the smallest known galaxy that harbors a huge, supermassive black hole at its core. NASA made this shocking discovery using its Hubble Space Telescope and found a new dwarf galaxy — known as M60-UCD1 — that crams 140 million stars within a diameter of about 300 light-years, which is only 1/500th the diameter of the Milky Way galaxy.
At the core of this tiny galaxy is what NASA is calling a “supermassive,” or “monster” black hole, one that has five times the mass of the black hole at the center of our own Milky Way galaxy. A dwarf galaxy is one that has a small fraction of the hundreds of billions of stars in the Milky Way.
In comparison of the Milky Way and the newly-discovered galaxy, NASA said looking at the nighttime sky from Earth reveals about 4,000 stars. Someone looking up into the sky from inside M60-UCD1 would see a million stars.
The supermassive black hole at the core of the Milky Way has a mass of about 4 million suns, taking up less than 0.01 percent of the galaxy’s estimated total mass, which is about 50 billion suns. In comparison, the super massive black hole that may lie in the core of M60-UCD1 appears five times larger than the one in the Milky Way, and also seems to make up about 15 percent of the dwarf galaxy’s mass, which is about 140 million suns.”That is pretty amazing, given that the Milky Way is 500 times larger and more than 1,000 times heavier than the dwarf galaxy M60-UCD1,” said Anil Seth, the University of Utah astronomer who led a study about the newly-found galaxy.
According to NASA, this finding indicates there could be many other dense galaxies throughout the universe that also have giant black holes. At the same time, the space agency said, the discovery may mean that dwarf galaxies like M60-UCD1 could be the ripped remnants of larger galaxies that broke apart during violent events such as collisions with other galaxies.
“We don’t know of any other way you could make a black hole so big in an object this small,” said Seth.
NASA explained that black holes are “gravitationally collapsed, ultra-compact objects that have a gravitational pull so strong that even light cannot escape.”