Question

What is a quasar? How were they discovered? During this process, taking the light from the quasar and passing it through a prism allowed us to determine what about the quasar? Explain how this led to the conclusion that they are very far away.

Answer 1

a massive and extremely remote celestial object, emitting exceptionally large amounts of energy, which typically has a starlike image in a telescope. It has been suggested that quasars contain massive black holes and may represent a stage in the evolution of some galaxies.

The first quasars  were discovered in the late 1950s, as radio sources in all-sky radio surveys. Theywere first noted as radio sources with no corresponding visible object. ... Astronomers had detected what appeared to be a faint blue star at the location of the radio source and obtained its spectrum.