Hubble Finds Smallest Known Galaxy With A Supermassive Black Hole

The discovery has astounded astronomers

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© 2017 NASA, ESA, STScI-PRC14-41a

Astronomers using data from NASA’s Hubble Space Telescope and from ground observation have uncovered an unexpected object in a very unlikely place - a gaping supermassive black hole hiding inside one of the smallest galaxies ever known, M60-UCD1.

The newly discovered black hole is five times as big as the one in our Milky Way galaxy. M60-UCD1 is one of the densest galaxies on record - it contains about 140 million stars within a diameter of about 300 light-years, which is only 1/500th of our galaxy’s diameter, according to NASA. To give you an idea, it would mean that if we lived in this galaxy at least one million stars would be visible to the naked eye. This compares to the 4,000 we can see on Earth. 

The find indicates that this phenomenon occurs in other tiny galaxies. It also leads to the idea that tiny galaxies may be offshoots of larger galaxies that were blown apart during collisions, rather than spontaneously born in isolation.

University of Utah astronomer Anil Seth, lead author of an international study of the dwarf galaxy published in Thursday’s issue of the journal Nature, said, “we don’t know of any other way you could make a black hole so big in an object this small.”

“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.”