APOD
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.
Spokes in the Helix Nebula
Explanation: At first glance, the Helix Nebula ( aka NGC 7293 ), looks simple and round. But this well-studied example of a planetary nebula , produced near the end of the life of a sun-like star, is now understood to have a surprisingly complex geometry . Its extended loops and comet-shaped features have been explored in Hubble Space Telescope images. Still, a 16-inch diameter telescope and camera with broad and narrow band filters was used to create this sharp view of the Helix. The color composite also reveals the nebula's intriguing details, including light-year long, bluegreen radial stripes or spokes that give it the appearance of a cosmic bicycle wheel. The spoke features seem to indicate that the Helix Nebula is itself an old and evolved planetary nebula. The Helix is a mere seven hundred light years from Earth, in the constellation Aquarius .
| Date | September 4, 2008 |
|---|---|
| Credit | Credit & Copyright: Don Goldman , Sierra Remote Observatories |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



