Polo's Bolos

Polo's Bolos were an astronomical object, a pair of black holes orbiting each other 15 light-years from Ellison's star. Massive gravimetric disruptions caused by their erratic orbits produced an anomaly called the galactic whirlpool.

History
In 2117, Polo's Bolos were discovered by the . The captain of the ship was curious to discover the cause of irregular X-ray emanations appearing to coming from a neutron star. As the ship approached the star, the crew were surprised to find that the emanations came from behind the star, which had been directly in the line of sight between Earth and the phenomena. Once the ship was close enough to see around the neutron star, the Marco Polo found the source of the signal: two black holes orbiting each other in an unusually-elliptical orbital pattern, like the swirl of bolas.

Polo's Bolos were moving and were on a trajectory to enter Earth’s solar system in three million years.