NuSTAR Bringing the High Energy Universe into Focus

When scientists detected the gamma-ray burst known as GRB 221009A on Oct. 9, 2022, they dubbed it the brightest of all time, or BOAT. Most gamma-ray bursts occur when the core of a star more massive than our Sun collapses, becoming a black hole. These events regularly release as much energy in a few minutes as our Sun will release in its entire lifetime.

Researchers have observed the X-ray emission of the most luminous quasar seen in the last 9 billion years of cosmic history. The new perspective sheds light on the inner workings of quasars and how they interact with their environment.

In a recent study published in The Astrophysical Journal, researchers report a first-of-its-kind measurement of a ULX taken with NASA's Nuclear Spectroscopic Telescope Array (NuSTAR). The finding confirms that these light emitters are indeed as bright as they seem and that they break the Eddington limit.