CCD image taken with a ST-1301E CCD camera thru Kopernik’s 20 inch F/8.1 telescope working at F/5.3. The exposure was 60 minutes. The field of view is approximately 20x25 arc minutes, with North at the top.
NGC 7293 (The Helix Nebula), in the Constellation of Aquarius, is probably the nearest of the planetary nebulae. In a small backyard telescope, or even large binoculars, it appears as a large but dim ghostly glow, a little dimmer in the center.
The Helix appears to be a filled doughnut of material, but astronomers now believe that it is actually a tube of gas pointed directly at Earth. It is this orientation that makes it look like a doughnut. The central star, which created the nebula, is a white dwarf star. The teal blue/green color in the center comes from the doubly ionized Oxygen (O-III) that it contains, while the red color is from ionized Hydrogen (H-II). The Kopernik image above shows a little of the dim outer parts of the nebula (upper left), and the comet-like shapes pointing toward the central star. The Helix Nebula is about 690 light years away.
Planetary Nebulae: To learn more about them, click here
George Normandin, KAS
November 10th, 2008