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.

2007 January 30
See Explanation.  Clicking on the picture will download 
the highest resolution version available.

Thor's Helmet from CFHT
Credit & Copyright: Jean-Charles Cuillandre (CFHT) & Giovanni Anselmi (Coelum Astronomia), Hawaiian Starlight

Explanation: NGC 2359 is a striking emission nebula with an impressive popular name - Thor's Helmet Sure, its suggestive winged appearance might lead some to refer to it as the "duck nebula", but if you were a nebula which name would you choose? By any name NGC 2359 is a bubble-like nebula some 30 light-years across, blown by energetic winds from an extremely hot star seen near the center and classified as a Wolf-Rayet star. Wolf-Rayet stars are rare massive blue giants which develop stellar winds with speeds of millions of kilometers per hour. Interactions with a nearby large molecular cloud are thought to have contributed to this nebula's more complex shape and curved bow-shock structures. NGC 2359 is about 15,000 light-years distant toward the constellation Canis Major.

Tomorrow's picture: ring crossing

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

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.