by Rod Pommier
Location: Pommier Observatory, Portland, OR, USA. Dates: 2012-07-24 through 2012-07-28. Telescope/mount: Celestron Compustar C14 with 0.75x focal reducer (f/8.3). Camera: SBIG STL 11000M with Baader Planetarium filters and SBIG AO-L adaptive optics at 8.5 Hz. Exposures: Exposures: H-alphaLRGB=180:175:84:84:84minutes=10hours:07minutes total exposure.
M27 lies about 1200 light-years from Earth. It's expansion rate indicates that the red giant that spawned it erupted between 3000 and 4000 years ago. The white dwarf remanant of the red giant lies at the center of the nebula. This image includes H-alpha data that show some of the subtle detail inside the nebula, as well as an additional outer shell of nebulosity that extends beyond the Dumbbell's familiar contours. The outer shell is material shed by the red giant star prior to the formation of the classic planetary nebula.