Using Wobbling Stellar Material, Astronomers Measure the Spin of a Supermassive Black Hole for the First Time May 22, 2024 — Astronomers have a new way to measure how fast a black hole spins ...
A black toenail can happen because of an injury that produces a bruise called a subungual hematoma, though it can also have other causes such as a nutritional deficiency or an infection. Black ...