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M57 (NGC 6720), The Ring Nebula, in Lyra
M57 is one of the most famous planetary nebulae, ie, the illuminated gases thrown off by a degenerating star. To the observer's eye, the nebula has the appearance of a perfect silvery-gray smoke ring, but to an imaging device, it has wonderful color. At its distance of 4100 lightyears, M57 is small, only about 2.5 arc minutes in diameter, or less than one-tenth the diameter of the moon.
| Date | 2005-06-03 |
| Scope | RCOS 12.5 inch Ritchey-Chretien telescope on an A-P 1200 GTO mount. Camera: SBIG ST-10XME with CFW8a filter wheel. Controlled with MaxIm 4.10. |
| Exposures | 25 minutes (5 x 5 min) each R, G, and B exposures with Astrodon filters. |
| Processing | Stacked and color combined in MaxIm, stretched in Photoshop CS2. |