SUPERCEDED-NEWER VERSION AVAILABLE---M27 - the Dumbbell Nebula - May 2011 version
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M27, the Dumbbell Nebula is a planetary nebula - a nebula created as a star is reaching its final days. As the star starts to burn out, it blows off a shell of gas. As this gas expands, it is heated by the star and shines. We see this shell as a planetary nebula.
In this photo, you can easily see the star that created the Dumbbell - it is the star that is exactly at the center of the nebula. M27 is an easy object in a telescope, as it shines brightly at magnitude 7.5 and is relatively large at about 8' wide (about 1/4 of the moon's apparent diameter).
In this image, North is Up. This image is cropped to 63% of the original full frame.
Exposure Details |
Lens |
Celestron C-8 SCT with Lumicon telecompressor |
Focal Length |
1100mm |
Focal Ratio |
f/5.5 |
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Mount |
Schaefer GEM - 7 1/2 |
Guiding |
Unguided |
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Camera |
Canon 20Da |
Exposure |
77 subexposures of 45 seconds each at ISO 1600 - total of just under 1 Hour |
Calibration |
30 darks, 30 flats, 30 bias |
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Date |
May 6, 2011 |
Temperature |
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SQM Reading |
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Seeing |
4 of 5 |
Location |
Pine Mountain Club, California |
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Software Used |
Images Plus 4.0 for camera control, calibration, stacking and digital development. Photoshop CS5 used for color correction, shadows and highlights, star shrinking, saturation adjustments, unsharp mask, and highpass filter. Noise Ninja for noise reduction.
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Notes |
I'm fairly happy with this exposure, although the telescope had a very fogged secondary mirror, and the collimation needed correction. The star density is very good, and I'm very pleased with the color saturation. |
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