The Cosmic Potter: How Rotation and Magnetic Fields Shape a Black Hole
On November 23, 2023, the LIGO, Virgo, and KAGRA detectors caught a gravitational wave from the merger of two black holes with masses of 137 and 103 solar masses. Both fall into the pair-instability mass gap, the range from 69 to 139 solar masses where ordinary stellar evolution leaves behind nothing but expanding gas.