But in the past two decades, new types of black holes have been seen and astronomers are beginning to understand how they form. Called supermassive black holes, they have been found at the center of pretty much every galaxy and are a hundred thousand to a billion times the mass of our sun.

To date, the collaboration has detected dozens of merger events since its first Nobel Prize-winning discovery. Early detected mergers involved either two black holes or two neutron stars. In 2021, LIGO/Virgo/KAGRA confirmed the detection of two separate "mixed" mergers between black holes and neutron stars.