IC 2177 - the Seagull Nebula in HaOIIIRGB
IC 2177 - the Seagull Nebula in HaOIIIRGB
IC 2177 - the Seagull Nebula in HaOIIIRGB
IC 2177 is an HII complex lying on the border of Monoceros and Canis Major. Covering over 3 degrees of sky, this beautiful nebula lies in one of the farthest arms of our Milky Way galaxy and is about 100 light years across.

The designation IC 2177 refers to the nebulosity spread across the wings of the Seagull. The head of the Seagull is Vdb 93, while the bright HII region at the bottom wing is Cedarblad 90. Also contained within the nebula are several open clusters - NGC 2343, NGC 2335, Collinder 465, and Collinder 466.

In this image, North is up.

Exposure Details
Lens Canon EF 200mm f/2.8L II USM
Focal Length 200mm
Focal Ratio f/3.5
 
Mount Schaefer GEM - 7 1/2 inch Byers gear
Guiding ONAG On-Axis Guider, Lodestar autoguider, PHD Guiding
 
Camera MonoMods Monochrome Canon 450D by Luis Campos and Gary Honis modified Canon 450D (Baader mod)
Exposure 29 RGB subs of 600 sec @ ISO 200 (4.8 hrs), 164 subs of 600 sec @ ISO 1600 (27 1/3 hours) using an Astronomik 6nm Ha clip filter, and 58 subs of 600 sec (9 2/3 hours) @ ISO 1600 using an Astronomik 12nm OIII clip filter (42+ hours total)
Calibration 30 darks, 30 flats, 30 flat darks, 30 bias
 
Date December 5, 8, 9, 30, and 31, 2013; January 1 and 20, 2014; February 19, 2014
Temperature 12/5-25F, 12/8-27F, 12/9-27F, 12/30-46F, 12/31-50F, 1/1-48F, 1/20-48F, 2/19-37F
SQM Reading Bortle 4 on all 8 nights - 12/5-21.15, 12/8-20.95, 12/9-20.95, 12/30-21.30, 12/31-21.50, 1/1-21.35, 1/20-21.20, 2/19-21.35
Seeing 2/19 - 2/5; 12/5,12/8, 12/9 and 1/20 - 3/5; 12/30 and 12/31 - 4/5; 1/1 - 5/5
Location Pine Mountain Club, California
 
Software Used Images Plus 5.75 for camera control, calibration, stacking, digital development, feature mask, smoothing and noise reduction, and multiresolution sharpening. Photoshop CS5 used for levels and curves, high pass filter, screen mask invert, selective color, HaOIIIRGB combining, and unsharp mask. Gradient Xterminator for gradient removal. Focus Magic for focus restoration. Registar for stack alignment and registration.
Notes This is my first light image with my new monochrome Canon 450D. I used the monochrome camera for capturing the narrowband Ha and OIII. I captured the RGB (color) and some of the Ha with the color camera. I'm very happy with the final result - the image has some nice color, the stars are very tight, and the Ha provides some good detail.