Barnard’s Loop is an emission nebula in Orion, and is part of the Orion Molecular Cloud Complex. The energy to ionize the loop presumably comes from the stars within the Orion Nebula. This area is home to many popular astrophotographical targets, including the Orion Nebula (M42), De Mairan’s Nebula (M43), the Running Man Nebula (NGC 1977), the Horsehead Nebula (B33), the Flame Nebula (NGC 2024), M78, NGC 2023, IC 431, IC 432, and IC 434. The loop is mostly contained within the 4 stars bordering this image (clockwise from the top right): Betelgeuse, Bellatrix, Rigel, and Saiph. The 3 Orion belt stars are also seen at the image center (from left to right): Alnitak, Alnilam, and Mintaka.
Technical details are as follows:
Barnard’s Loop itself was imaged from the Florida Keys during the Winter Star Party 2019, using the STL11K hooked up to a Canon EF 100-400mm f/4.5-5.6 IS II USM lens at 100 mm & f/4.5, sitting on top of a Paramount MyT. I acquired about 18 hours of Ha and 45 min/channel RGB of the region. Meanwhile Terry Park acquired higher resolution data of the M42/43 region with a 4″ refractor. While processing I layered in the M42/43 data as well as some of my older higher resolution data of the Horsehead and Flame Nebula regions.