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]
The Rosette Nebula is one of the most spectacular deep sky objects in the night sky. The clouds of gas are being stimulated by the radiation from the young stars in the open cluster at the center, NGC 2244. The nebula lies at an estimated distance of about 5,000 light years and spans a distance of roughly 130 light years, not quite fitting completely into the FOV of my imaging telescope used for this capture. Although imaged in all 3 common narrowband filters, I 'mixed' the colors to emulate a pink rose color while also showing some of the OIII emissions in the core in a blue color. Equipment: ZWO ASI1600MM-C Camera @ -15C and Gain:200 Offset:50 Software Bisque MyT Mount Stellarvue SVQ100 Astrograph Refractor, 580mm @ f/5.8 Innovations Foresight ONAG Software: Pixinsight Commercial Version 1.8 Lightroom CC Photoshop CC Innovations Foresight SkyGuard Light Frames: Ha: 56 x 240 secs (3 hrs 44 mins) OIII: 57 x 240 secs (3 hrs 48 mins) SII: 63 x 240 secs (4 hrs 12 mins) Red:40 x 30 secs (20 mins) Green:40 x 30 secs (20 mins) Blue: 40 x 30 secs (20 mins) 12 hrs 54 mins total Dark Frames: 10 x 30 secs, RGB (5 mins) 10 x 240 secs, Ha,OIII,SII (2 hrs) Bias Frames 60 Flat Frames 10 each filter
This shot of the aptly named North America Nebula (also known as NGC7000) shows detail in the 'wall' section - a very active Hydrogen Alpha emission portion of the nebula that glows in a reddish-salmon color in this natural color image. Additionally, a portion of the dimmer Pelican nebula (the 'beak' section) is visible protruding into the upper right portion of this image. Equipment: Canon 550D (astro-modified, clear glass filter) Software Bisque MyT Mount Stellarvue SVQ100 Astrograph Refractor, 580mm @ f/5.8 Software: Pixinsight Commercial Version 1.8 Lightroom CC Photoshop CC Light Frames: 14 x 360 secs 2 x 300 secs (1 hr 34 mins) Dark Frames: 15 x 360 secs (1 hr 30 mins) Other Frames: 30 Bias No Flats More details from Wikipedia: The North America Nebula (NGC 7000 or Caldwell 20) is an emission nebula in the constellation Cygnus, close to Deneb (the tail of the swan and its brightest star). The remarkable shape of the nebula resembles that of the continent of North America, complete with a prominent Gulf of Mexico. It is sometimes incorrectly called the "North American Nebula".[3]