M57 Ring Nebula
DETAILS: Imaged with the 12.5" Truss RC at f9, on an ME Robotic mount 07-16-04, using the AO-7 guided ST-10XME. Luminance unbinned at 110 minutes, RGB binned 2 at 30 minutes each channel. Aligned in RegiStar, RGB combined in MaxIm DL using the RC Console and color combine features. Luminance was given 3 iterations of CCDSharp before levels, curves and other processing in Photoshop CS including unsharp masking. LRGB combined in PS, and cropped to fit this page.
COMMENTARY: The Ring Nebula is one of the best known planetary nebula and is located about 1,200 light-years away in the Constellation Lyra. The star at the center of the Ring is a white dwarf, a dying star which has blown off its outer atmospheric envelopes and illuminated the expanding gas shells with strong stellar winds and radiation. Unlike M27 (Dumbell Nebula), seen side on, M57 is a torus shaped, half light-year wide ring of gases blown outward from the collapsing star some 20,000 years ago.