The Seagull Nebula (IC 2177) is an emission nebula between the constellations Monoceros and Canis Major. It emits in all the of the main emission bands used in amateur astrophotography, Hα, OIII, and SII. This rendition uses the SHO palette with some of the Hα green contribution reduced to bring out the subtle coloring in the weaker OII and SII channels. From Wikipedia: IC 2177 is a region of nebulosity that lies along the border between the constellations Monoceros and Canis Major. It is a roughly circular H II region centered on the Be star HD 53367.[5] This nebula was discovered by Welsh amateur astronomer Isaac Roberts and was described by him as "pretty bright, extremely large, irregularly round, very diffuse."[6] The name Seagull Nebula is sometimes applied by amateur astronomers to this emission region, although it more properly includes the neighboring regions of star clusters, dust clouds and reflection nebulae. This latter region includes the open clusters NGC 2335 and NGC 2343.[7] Equipment: QHY268M Camera @ -10C and Gain:56 Offset:25 Software Bisque MyT Mount Stellarvue SVQ100 Astrograph Refractor, 580mm @ f/5.8 Antlia Pro Filters (3nm narrowband plus LRGB) Askar FMA180 Guidescope/ASI290MM Software: Pixinsight Commercial Version 1.8 Lightroom CC Photoshop CC N.I.N.A. Control Software BlurXTerminator (Russell Croman) Star XTerminator (Russell Croman) Noise XTerminator (Russell Croman) Light Frames: Ha - 14 x 480 secs ( 1 hr 52 mins) OIII - 14 x 480 secs (1 hr 52 mins) SII - 11 x 480 secs (1 hr 28 mins) Red: 14 x 30 secs (7 mins) Green: 13 x 30 secs (6 mins 30 secs) Blue: 13 x 30 secs (6 mins 30 secs) 5 hrs 32 mins total Dark Frames: 10 x 30 secs (5 mins) 10 x 480 secs (1 hr 20 mins) Flat Frames: 10, each filter Bias Frames: 60
These 2 nebulae are often imaged together, and therefore have taken on related colloquial names. The Spider Nebula (IC417) is right of middle with the Fly Nebula (NGC1931) shown directly below. I also see a large insect with antennae trundling into the top of the frame. 😄 2 star clusters can also be seen on the left side of the image, NGC1912 being the larger one towards the edge of the frame, and NGC1907 the smaller about 1/3 of the way into the frame from the left. This is a 3 band narrowband capture, but the OIII signal was weak and only seemed to appear in the center of the 2 nebulae. Stars were added from additional short captures in natural light. These 2 nebulae contain star forming regions and are estimated to be between 7,000 (Spider) and 10,000 (Fly) light years distant in the direction of the constellation Auriga. Equipment: QHY268M Camera @ -10C and Gain:56 Offset:25 Software Bisque MyT Mount Stellarvue SVQ100 Astrograph Refractor, 580mm @ f/5.8 Antlia Pro Filters (3nm narrowband plus LRGB) Askar FMA180 Guidescope/ASI290MM Software: Pixinsight Commercial Version 1.8 Lightroom CC Photoshop CC N.I.N.A. Control Software Star XTerminator (Russell Croman) Noise XTerminator (Russell Croman) Light Frames: Ha - 44 x 480 secs ( 5 hrs 52 mins) OIII - 44 x 480 secs ( 5 hrs 52 mins) SII - 41 x 480 secs (5 hrs 28 mins) Red: 24 x 30 secs (12 mins) Green: 24 x 30 secs (12 mins) Blue: 24 x 30 secs (12 mins) 17 hrs 48 mins total Dark Frames: 10 x 30 secs (5 mins) 10 x 600 secs (1 hr 40 mins, optimized) Flat Frames: 10, each filter Bias Frames: 60
Here is another M13 image, this time using the refractor for a wider view. M13 is one of the larger and more impressive globular clusters visible, and makes for an interesting target in almost any scope. This image is an RGB composite with just a little of the luminance data blended in to get some glow in the core without washing out the colors. Equipment: ZWO ASI1600MM-C Camera @ -15C and Gain:0 Offset:10 Software Bisque MyT Mount Stellarvue SVQ100 Astrograph Refractor, 580mm @ f/5.8 Software: Pixinsight Commercial Version 1.8 Lightroom CC Photoshop CC Light Frames: Luminance: 50 x 30 secs (25 mins) Red:50 x 60 secs (50 mins) Green:50 x 60 secs (50 mins) Blue: 49 x 60 secs (49 mins) 2 hrs 54 mins total Dark Frames: 10 x 30 secs, RGB (5 mins) 10 x 60 secs, Luminance (10 mins) Bias Frames 60 Flat Frames 10 each filter More from Wikipedia: Messier 13 or M13, also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster, is a globular cluster of several hundred thousand stars in the constellation of Hercules. About 145 light-years in diameter, M13 is composed of several hundred thousand stars, the brightest of which is a red giant, the variable star V11, also known as V1554 Herculis,[12] with an apparent visual magnitude of 11.95. M13 is 22,200–25,000 light-years away from Earth.[13]
