Brian D. Metzger

Scientists simulated the birth of black holes from massive stars and saw that magnetic fields act as a cosmic brake. A strong field slows the hole's spin, a weak one spins it up to near-light speed. This explained why detectors occasionally see pairs of heavyweight black holes, like the record-break

Astronomers have found that mysterious blue flashes prefer dwarf galaxies but avoid regions of new star formation. This indicates their nature: a merger of a dead neutron star with a massive dying star — not an explosion, but a collision.