What is #21: A Quasar?

The 'What Is' Series

A couple of months ago I started a new series on this blog titled "What Is". Thus far the focus is on the field of astronomy where we hear all sorts of cool science taking place in space. The goal of this series is to explain the details of different objects we hear about relatively frequently.

Quasars

Quasars are cool, science fiction sounding objects, but what exactly are they? Are they real objects or are they truly science fiction? Although they sound like science fiction, quasars are real astronomical objects. The word 'quasar' stands for quasi stellar objects. Still sounds like science fiction, but they are still real objects! Quasars are galaxies that have centers that are very active. Large galaxies, such as the Milky Way galaxy, have very large black holes at the center with several million suns worth of mass. This is also true for quasars, but what makes a quasar a quasar is the large amount of material falling into the black hole. When this happens a great amount of energy is released, making the galaxy appear very active in the center and very luminous.

Artist's impression of a quasar. - NASA

A galaxy such as ours was possibly once a quasar, but now it is relatively quiet. It still releases energy from material falling into a black hole, but quasars have the luminosity, or brightness, several thousand times that of our current galaxy. 

There you go. Quasars may sound like science fiction, but they are real objects in our amazing universe!