At the end of January we had a few clear nights although with a pretty significant moon up. I managed to get about 5 hours of exposure time and here is what came out. Here is the complete writup for anyone interested:
The Rosette Nebula (NGC 2237) is one of the most popular and often photographed deep sky objects. It is officially referred to by astronomers as an “H II region” and is a small part of a giant molecular cloud in the constellation Monoceros (the Unicorn), about 5,200 light years from us in our Milky Way Galaxy. The cloud (nebula) near the star cluster NGC 2244, seen in the center of the image, is fluorescing from the intense ultraviolet light emitted by the stars that recently, at least in stellar time, were formed from the same nebula. The powerful stellar wind emitted by the stars in the cluster has carved a hole in the middle of the Rosette and is eroding away the cloud around them. If you enlarge the image or look at the enlarged center image, also posted here, you will be able to see black globules at the head of extended dark tendrils. Those are protostars, called “Bok Nebulae” where the less dense surrounding molecular cloud has been pushed back by the stellar wind, leaving exposed the contracting globule that potentially will become a star. In infrared, those nascent stars can be seen glowing a dark red as their fusion furnaces begin to ignite.
This image is composed of 60, 300-second exposures through narrow band filters admitting only the light frequencies emitted by hydrogen, oxygen, and sulfur, technically known as Hydrogen-alpha, Oxygen III, and Sulfur II, from our backyard in Salado, TX (Bortle 5 sky). Those light frequencies were then mapped to green, blue, and red, respectively, to produce a false-color image in what is known as the “Hubble Palette,” so named because of its extensive use in images captured by the Hubble Space Telescope.
For those interested in such things, the data for the image was collected using a ZWO ASO2600MM Pro camera, with a ZWO AFW filter wheel, ZWO 7nm 36mm filters, and a ZWO EAF auto focuser, through an Askar V telescope in its 60mm aperture, 294mm focal length with its 0.75 reducer, mounted in a ZWO AM5 equatorial harmonic drive and tripod and controlled by a ZWO ASIAIR Plus minicomputer mounted on the telescope. The guide camera was a ZWO ASI120MM Mini mounted on a ZWO ASI 30mm F/4 mini guide scope. Registration, stacking, and combining the data into an image was accomplished using Astro Pixel Processor and Adobe Lightroom Classic.