NGC 7129 - A Reflection Nebula in Cepheus
|
|
NGC 7129 is a stellar nursery surrounded by a blue reflection nebula. The brightest stars in this very young cluster are hot, blue stars. The surrounding dust reflects this blue light towards us. Also contained within the nebula are several deep red crescent shaped "Herbig-Haro" objects. These red regions are where red hydrogen gas has been compressed by shock waves originating from the young stars.
Photographically, NGC 7129 is about 7 arc minutes in diameter, and has a very low surface brightness. As such, it makes for a challenging object to image.
In this image, North is up. This image is cropped to 59% of the original full frame.
Exposure Details |
Lens |
Celestron C-8 SCT with Celestron focal reducer |
Focal Length |
1160mm |
Focal Ratio |
f/5.8 |
|
Mount |
Schaefer GEM - 7 1/2 Byers gear |
Guiding |
ONAG On-Axis Guider, Lodestar autoguider, PHD Guiding |
|
Camera |
Canon 450D - Gary Honis modified |
Exposure |
171 subexposures of 180 seconds each at ISO 1600 - 8 1/2 hours total |
Calibration |
30 darks, 30 flats, 30 bias |
|
Date |
August 15, 16, 18, and 19, 2012 |
Temperature |
68F on all 4 nights |
SQM Reading |
21.2 (Bortle 4) on 8/15, 8/18, and 8/19, 21.3 (Bortle 4) on 8/16 |
Seeing |
4/5 on 8/15 and 8/19, 5/5 of 8/16 and 8/19 |
Location |
Pine Mountain Club, California |
|
Software Used |
Images Plus 4.5 for camera control, calibration, stacking, digital development, adaptive Richardson-Lucy deconvolution, multiresolution sharpening, smoothing and noise reduction. Registar used for stack alignment. Photoshop CS5 used for levels and curves, color correction, selective color, match color, high pass filter, star shrinking, lab color, saturation adjustments, screen mask invert, hdr toning, and smart sharpen. Gradient Xterminator for gradient removal. Carboni Tools for additional saturation adjustments, noise reduction, and smoothing. HLVG for additional color correction. |
Notes |
While I'm generally fairly happy with this image, I think it could have benefited from some more imaging time. I had to push the processing fairly hard, and I couldn't bring out as much separation between the faint parts of the nebula and the surrounding dark nebula. Due to the subtleness of the nebula, I found this to be a very difficult image to process.
This image won 1st place in Cloudy Night's September 2012 DSLR Challenge contest. |
|
|