The field of clusters and nebulosity in Gemini, with Messier 35 the main open star clusters here. Below M38 is NGC 2158. The nebulosity at left between Mu and Eta Geminorum is IC 443, a supernova remnant, aka the Jellyfish Nebula. The nebula at bottom is IC 2174, just over the border in Orion and aka the Monkeyhead Nebula. The field is similar to that of binoculars. This is a stack of 10 x 3-minute exposures with the filter-modified Canon 5D MkII at ISO 800 and 200mm Canon L-Series lens at f/2.8. Some light haze passing through in some exposures added the natural star glows. I left those in as part of the stack to add the glows. Taken with the Fornax Lightrack tracker as part of testing. Taken from home on a rare fine and mild winter night, January 4, 2019. Diffraction spikes added with Astronomy Tools.
This is a two-panel mosaic of nebulas and clusters in southern Gemini and northern Orion. The Messier 35 star cluster is at top accompanied by the smaller cluster NGC 2158. At left near the orange star Eta Geminorum is the crescent-shaped Jellyfish Nebula, IC 443, a supernova remnant. The fainter, diffuse nebula at far left is IC 444. At bottom and over the border in Orion is the Monkeyhead Nebula, NGC 2174. The little round nebula above NGC 2174 is Sharpless 2-247. This is a mosaic of two segments for the northern and southern halves of the scene, with each half being a stack of 6 x 8-minute exposures at ISO 800 with no filter, plus a stack layered in of 6 x 8-minute exposures at ISO 3200 with an Optolong L-Enhance filter to bring out the faint red nebulosity. So this is a stack and blend of a total of 24 exposures. Alll were with the Canon EOS Ra camera on the SharpStar HNT150 Hyperbolic Newtonian astrograph at f/2.8.
This is the region of central Cassiopeia containing a rich assortment of deep-sky objects: The so-called Ghosts of Cassiopeia nebulas at top, the Owl Cluster, aka the ET Cluster, at bottom, and the Pacman Nebula at right. The Ghosts of Cassiopeia are the magenta/cyan reflection and emission nebulas officially called IC 59 and IC 63. Both are reflecting the light of bluish Gamma Cassiopeiae, aka Navi. The "Ghost" name for these objects is a recent appellation. See https://apod.nasa.gov/apod/ap191025.html The star cluster at bottom is NGC 457, with smaller NGC 436 above it. It is variously called the Owl Cluster or the E.T. Cluster. The emission nebula at right is the Pacman Nebula, NGC 281, below the stars Eta (Achird) and Alpha (Schedar) Cassiopeiae. The blue star at far left is Delta Cassiopeiae, aka Ruchbah. It along with Gamma and Alpha form the middle three stars of the W of Cassiopeia. The field here is 7.5° x 5°, similar to binoculars. This is stack of 8 x 16-minute exposures through an IDAS NB1 nebula filter to bring out the faint nebulosity, blended with a stack of 15 x 8-minute exposures with an Astronomik UV/IR Cut filter for a white light normal colour image. All with the Canon Ra (at ISO 1600 for the NB1 filter shots and at ISO 1000 for the normal shots) through the SharpStar EDPH 61mm refractor at f/4.5. All stacking, alignment and blending with Photoshop. No LENR or darks applied, just inter-frame dithering to eliminate thermal noise specks which were prominent in the long high-ISO filtered shots. Autoguiding and dithering was with the MGEN3 stand-alone autoguider. Faint nebulosity was brought out with luminosity mask adjustments with Lumenzia.
