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Active galactic nucleus

Adapted from Wikipedia · Explorer experience

A stunning image of the quasar 3C 273 taken by the Hubble Space Telescope, showing one of the brightest and closest quasars to Earth.

Active Galactic Nucleus

An active galactic nucleus (AGN) is a very bright spot right in the middle of some galaxies. This special spot shines with lots of energy in many kinds of light, like radio, microwave, infrared, optical, ultra-violet, X-ray, and gamma ray. The light does not come from stars. Scientists think it comes from a giant supermassive black hole at the center of the galaxy.

Our own galaxy, the Milky Way, has a supermassive black hole too, but it is not active right now. It was active a long time ago, about 8 billion years back.

AGNs are some of the brightest things we can see in space. Because they are so bright, we can see them even when they are very far away. Looking at AGNs helps scientists understand how the universe changes and how it works. Some AGNs are called quasars, and a special kind called a blazar has a jet pointing toward Earth, which makes it look even brighter.

Fun Facts

  • AGNs can be seen across huge distances in space.
  • They shine in many kinds of light, from radio waves to gamma rays.
  • Scientists study AGNs to learn more about the universe and how it has changed over time.

Famous AGNs

Some well-known galaxies with AGNs are:

Images

This image shows the first ever picture of a black hole, captured by a global team of telescopes. The dark shadow in the center is the black hole itself, located at the center of a galaxy!
A stunning view of a powerful jet of energy streaming from the center of galaxy M87, captured by the Hubble Space Telescope.
Diagram showing different views of an active galactic nucleus, helping us understand how these powerful objects in space can look different depending on our viewpoint.

This article is a child-friendly adaptation of the Wikipedia article on Active galactic nucleus, available under CC BY-SA 4.0.

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