Gargantua in the Mist: A Precocious Black Hole Behemoth at the Edge of Cosmic Dawn

The non-detection of J1342+0928 in the DECaLS z-band image (top left), despite its brightness beyond 1 micron in the Magellan image (top right), identifies it as an interesting distant object. From the spectrum of the object (taken with Gemini, Magellan, and LBT), which identified it as the most distant quasar known, the research team also measured the mass of its supermassive black hole.