Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

Astronomy 101: Quasars and other AGNs

In this episode, discover what powers some of the most extreme objects in the universe — quasars and other active galactic nuclei.
RELATED TOPICS: QUASARS | BLAZARS | BLACK HOLES
Quasar-3C-273
3C 273 was the first quasar whose spectrum was identified. // NASA/STScI
Astronomers know that a giant black hole sits in the center of each large galaxy. This black hole can weigh anywhere between a few million times our Sun’s mass to tens of billions of times our Sun’s mass.

A black hole’s extreme mass means it has a huge gravitational force that pulls in all material nearby — like, from a passing gas cloud or star — to form a disk of gas and dust around the black hole. Friction in this accretion disk causes it to glow, and that light energizes more nearby material. Thus, the area surrounding the supermassive black hole glows in visible, ultraviolet, and X-ray light. When a galaxy’s central black hole is pulling in material and glowing, astronomers call it an active galactic nucleus, or AGN. The brightest and most energetic type of AGN is a quasar.

The full text of this article is available to registered users of Astronomy.com. Register now!

Registration is FREE and takes only a few seconds to complete. If you are already registered on Astronomy.com, please log in below.
ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
BoxProductcovernov

Click here to receive a FREE e-Guide exclusively from Astronomy magazine.

Find us on Facebook

Loading...