Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2000 July 11
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

The Crab Nebula in Blue and White
Credit & Copyright: Jay Gallagher (U. Wisc.), WIYN, AURA, NOAO, NSF

Explanation: The Crab Nebula is a complex shell of expanding gas. The Crab Nebula formed from a star that was seen to explode in a supernova about 1000 years ago. This two color composite image taken with the WIYN 3.5-meter telescope shows in great detail filamentary structure of the glowing hydrogen gas. Also known as M1, the center is home to a dense neutron star, a star as massive as our Sun but only the size of a city. The neutron star is a pulsar that spins thirty times a second and spits out energy that powers the nebula. The nebula is named from its likeness to a crab in an early drawing. The Crab Nebula still presents mysteries today as the total mass of the nebula and pulsar appears much less than the mass of the original pre-supernova star!

Tomorrow's picture: Giant Starspot

< | Archive | Index | Search | Calendar | Glossary | Education | About APOD | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/GSFC
& Michigan Tech. U.