Not one but two gigantic black holes lurk at the heart of the distant spiral galaxy NGC 7674, a new study suggests.
These two supermassive black holes are separated by less than 1 light-year and together harbor about 40 million times the mass of the sun, researchers said.
If it holds up, the find would be just the second known system of double supermassive black holes. The other, announced in 2006, is in a galaxy known as 0402+379, whose two giant black holes are separated by about 24 light-years and boast a combined 15 billion solar masses. [No Escape: Dive into a Black Hole (Infographic)]
(The Laser Interferometer Gravitational-Wave Observatory project, or LIGO, has spotted the gravitational waves emitted by multiple binary black holes as they spiral toward each other. But the LIGO detections involve objects a few tens of times more massive than the sun, known as stellar-mass black holes.)
The research team analyzed observations of NGC 7674, which lies ab...