In June 2020, astronomers reported details of a compact binary merging, in the " mass gap " of cosmic collisions, of a first-ever 2.50–2.67 M ☉ "mystery object", either an extremely heavy neutron star (that was theorized not to exist) or a too-light black hole, with a 22.2–24.3 M ☉ black hole, that was detected as the gravitational wave GW190814.