M57, The Ring Nebula in Lyra


(Click on image for full size version)


Description: The ring nebula is one of the brightest planetary nebula in the sky.  It was formed when the central star, here visible as blue, ejected its outer shell of material.  20 hours of H alpha data was blended with the image to show a secondary and tertiary outer shell.  The latter is almost perfectly spherical.  To the upper right is IC1296, a small irregular galaxy.
Exposure Data: 5/16-23/2005.  L: 27x5m, Ha: 59 x 20m, RG: 15 x 5m, B: 15x7m. HaRGB binned 2x2.  -25C, 0.55 arc-sec./pixel.
Processing: Multi-night automatic acquisition and dithering via CCDAutoPilot2 and CCDSoft, reduced and aligned, in Mira, L: 50 iterations RL decon, L+Ha combine, curves, levels, Gradient Xterminator  and other processing in Photoshop.
Optical System: 14.5 Ritchey-Chretien @ F/9 w/FFC, IMG6303E/CFW-7 CCD camera, AstroDon filters, Paramount ME, dithered 3 pixels, off-axis guided .
Comments: The background is raised to show the very faint tertiary shell.  Total imaging time is 26 hours.  Here is the Ha data only.  The Spitzer Space Telescope also imaged this object.