The Belt of Orion with the Horsehead Nebula at botton, the dark nebula set in the bright emission nebula IC 434. The nebula at left of the Zeta Orionis (aka Alnitak) is the Flame Nebula, NGC 2024. The reflection nebula at upper left is the M78 complex with NGC 2071. The other Belt stars are Alnilan (centre) and Mintaka (upper right). The field contains a wealth of other blue reflection and red emission nebulas. Taken from Australia, March 2014 with the Borg 77mm astrographic apo refractor (330mm focal length) at f/4.3 for a stack of 5 x 10 minute exposures with the filter-modified Canon 5D Mark II at ISO 800.
A mosaic of the region in Cassiopeia and Cepheus containing the main nebulas: the Bubble Nebula (NGC 7635) at lower left, and the Cave Nebula (Sh 2-155) at upper right. At left is also the bright Messier open cluster M52. The small yellowish cluster at right is NGC 7419. The small cluster at lower centre is NGC 7510. The small nebula just left of centre is NGC 7538. This is a mosaic of 4 panels, each segment being a stack of 10 x 6-minute exposures taken over two nights with the TMB 92mm apo refractor at f/4.4 with the Borg 0.85x field flattener/reducer and the filter-modified Canon 5D MkII at ISO 800. Images stacked and merged in Photoshop. Shot from New Mexico.
This is the California Nebula (aka NGC 1499) in Perseus, a classic red emission nebula emitting mostly at the red wavelength of hydrogen-alpha light but also with a strong hydrogen-beta emission line in the blue-green part of the spectrum. By contrast, below is the small blue reflection nebula known only as IC 348, a cloud of dust surrounding hot blue stars and reflecting their light. But the region also contains some dim red emission nebulosity. Also throughout the field are patches of yellow-brown dust that form obscuring dark nebulas. The main dark nebulas are Barnard 5 (above IC 348) and Barnard 4 below. This is a stack of 8 x 8 minute unfiltered exposures at ISO 800 blended with a stack of 9 x 15-minute exposures through an Optolong L-Enhance narrowband filter, to bring out the emission nebulas. All were with the Canon EOS Ra camera through the William Optics RedCat 51mm astrograph at f/4.9, equipped with the Starizona filter drawer. Autoguiding was with the Lacerta MGEN3 stand-alone autoguider on the Astro-Physics Mach 1 mount. All stacking, alignment and blending was with Photoshop. Luminosity masks applied with Lumenzia to do selective curves adjustments to various tonal ranges. Shot from home November 15, 2020.
