NGC7293, The Helix Nebula in Aquarius

 

(Click on image for full size version)

 

Description: This is one of the largest planetary nebula and the closet to earth at an estimated distance of 450 ly.  It is very large with the brightest portion approximately half the size of the full moon.  Its outer shell, a portion of which can be seen in the lower right, extends to nearly the diameter of the full moon.  The blue-white central star is apparent in the center of the nebula.
 
Exposure Data: 10/13/2003.  RRGB: 12x5m, 4x3m, 4x3m.  GB 2x2. -10C, 1.1 arc-sec./pixel.
 
Processing: Acquired via Sequencer II (dither 4) and CCDSoft, reduced and aligned, in Mira, Combined in Sigma, L 2x CCDSharp, RGB combine in Maxim, LRGB combine, curves, levels and other processing in Photoshop.
 
Optical System: BRC-250, 10 Baker-Ritchey-Chretien @ F/5, ST-10XME NABG/CFW-8A CCD camera, Paramount ME.  autoguided
 
Comments: Average FWHM was 3.8 arc-sec., deconvolved to 3.1 arc-sec.