The Crab Nebula Is The Supernova That Shone During The Day

When a star explodes in a giant supernova, it leaves quite an impression on the universe. There are plenty of supernova remnants, known as nebulae, visible by telescope, though because of their distance we're seeing them as they were hundreds of millions or even billions of years ago. Rarely do we get to see one in the act of exploding by telescope; much less with the naked eye. But that's exactly what happened when the Crab Nebula formed nearly a millennium ago.

Related: The Bubble Nebula Is a Giant Soap Bubble In The Sky

A Historic Explosion

Astronomers first observed the Crab Nebula in the constellation Taurus on July 4, 1054. The explosion was so bright that it was visible during the day for 23 days, and remained visible at night for almost two years. It didn't get its name until 1844, when British astronomer William Parsons produced a sketch of the nebula that resembled a crab.

Related: The Boomerang Nebula Is The Coldest Place In The Known Universe

The Crab Nebula Today

The bright designs of the Crab Nebula come from a filamentary structure of hot gasses combined with a mass of electrons trapped within the leftover pulsar's powerful magnetic field. Only 6,500 light-years from Earth, the nebula is close enough that you can observe it with low-powered binoculars at night—but you won't see much more than a dim spot in the sky.

Is there something you're curious about? Email us at editors (at) And follow Curiosity on Facebook, Instagram and Twitter.

Watch and Learn: Our Favorite Videos About Supernovae

The Supernova Of 1054

Hear the story of the supernova that rivaled our sun.

Key Facts In This Video

  1. When the supernova that became the Crab Nebula appeared in 1054, it was 4 times brighter than Venus. 00:04

  2. The Crab Nebula measures around 10 lightyears in diameter, which is far bigger than our solar system. 02:01

  3. The combined mass of the Crab Nebula and its pulsar is much less than what it should be, puzzling scientists. 02:58

Why Do Stars Explode?

Find out why these cataclysmic explosions happen.

Echoes Of A Supernova

One 17th century supernova should have been visible in the sky. Why wasn't it?

Written by Curiosity Staff June 17, 2015

Curiosity uses cookies to improve site performance, for analytics and for advertising. By continuing to use our site, you accept our use of cookies, our Privacy Policy and Terms of Use.