M57 – The Ring Nebula

 

Like other "planetary nebulae," the Ring Nebula in the constellation Lyra is the expelled outer envelope of a star that has reached the final stages of its life. This bubble of gas is more than 2,000 light years away and is more than one light year in diameter. The central star emits huge amounts of UV radiation which excites the gas bubble and makes it glow.


M57, the Ring Nebula

Equipment Celestron 9¼" at f/10 on a Celestron CGE equatorial mount
SBIG ST-8XM camera
SBIG AO-7 adaptive optics
Optec IFW filter wheel with Astrodon TruBalance LRGB filters
Optec TCF-S focuser
Exposure
Luminance   17 x 5 minutes, binned 1x1, -10°C
Red   5 x 5 minutes, binned 2x2, -10°C
Green   5 x 5 minutes, binned 2x2, -10°C
Blue   5 x 5 minutes, binned 2x2, -10°C
Processing Luminance master dark frame: 55 x 5 minutes, sigma-reject combined
Color master dark frame: 47 x 5 minutes, sigma-reject combined
Dark and flat frame reduction in CCDSoft
Luminance images combined in Ray Gralak's Sigma Clip pre-Beta 11
Color images average-combined CCDSoft
Processing and LRGB-combined in Photoshop CS
Date and Location 27/28 August 2004    Montpelier, VA    N 37° 49' 12", W 77° 42' 06"