LIGO and Virgo detected a collision between a black hole and a mystery object
Gravitational wave measurements put the object’s mass between a neutron star and a black hole
![Black hole collision illustration](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2020/06/062320_mt_ligo_feat.jpg?fit=1028%2C579&ssl=1)
In a first, the LIGO and Virgo gravitational wave detectors have spotted a collision between a black hole (illustrated left) and a mystery object (right), which could be either the heaviest neutron star ever discovered or the lightest black hole.
R. Hurt/MIT/Caltech/LIGO (IPAC)