'Dark' black hole wandering the Milky Way may be the smallest yet detected
The black hole is 5,000 light-years away and was discovered thanks to the power of its gravity to act as a gravitational lens,
Sahu's team used the Hubble Space Telescope to follow up on the discovery,
the black hole has a mass about 7.1 times greater than the sun's mass.
Stellar-mass black holes are the product of the supernovae of stars with masses 20 times greater than the Sun
when stars with between 8 and 20 solar masses go supernovae, they leave behind a neutron star instead
Neutron stars can theoretically have masses up to about 2.3 solar masses
stellar-mass black holes detectable in binary systems have not turned up any with less than 5 solar masses,