A team of researchers led by Miyuki Kaneko at Japan's Keio University used data from the James Clerk Maxwell Telescope to identify an unusual cloud of gas about 27,000 light-years away in the constellation Sagittarius.
They combined this with information from the National Astronomical Observatory of Japan's Nobeyama 45-m Radio Telescope to discover the object, which has been dubbed a 'Space Tadpole'.
The curved 'Tadpole' shape of the molecular gas cloud strongly suggests that it is being stretched as it orbits around a massive compact object.
At the centre of the Tadpole's orbit, there are no bright objects which could be massive enough to gravitationally hold the Tadpole.
The best candidate for this massive compact invisible object is a black hole. Because black holes don't emit light, the only way to detect them is when they interact with other objects.
This leaves astronomers in the dark about just how many black holes, and with what range of masses, might be lurking in the Milky Way. Now the team plans to use ALMA (Atacama Large Millimeter/submillimeter Array) to search for faint signs of a black hole, or another object, at the gravitational centre of the Tadpole's orbit.