What is a quasar and how do you observe it?

A quasar is a highly energetic and distant active galactic nucleus that emits massive amounts of electromagnetic radiation, including visible, ultraviolet, and X-ray light. These objects are powered by supermassive black holes that are surrounded by hot disks of gas and dust that are being pulled towards the black hole. As the gas and dust spiral towards the black hole, they release huge amounts of energy in the form of intense radiation.

Observing quasars can be challenging due to their extreme distance and brightness, as well as the fact that they are often obscured by intervening gas and dust. However, astronomers have developed a number of techniques for observing these objects, including using telescopes that are sensitive to the wavelengths of light emitted by quasars, such as radio and X-ray telescopes.