Horsehead Nebula and Flame Nebula
Designation: Barnard 33 (Horsehead) – NGC 2024 (Flame)
Distance: 1,000 – 1,500 light years
Object type: Dark nebula
The Horsehead Nebula and its inseparable companion, the Flame Nebula are one of the most iconic sights in the night sky, and one of the most photographed. The deep-red colour of this complex originates from ionised hydrogen gas (Hα) predominantly behind the nebula, and caused by the intense radiation from the nearby star Sigma Orionis. The darkness of the Horsehead, instead, is caused mostly by thick dust.
The two sit near Alnitak, the first star from the left in the Orion’s belt, and are part of a large, dark, molecular cloud known as the Orion Molecular Cloud Complex. The Horsehead Nebula is about 1,350 light years away whereas the Flame Nebula is estimated to be somewhat closer.
Mount: Sky-watcher HEQ5-Pro
Main Telescope: William Optics ZS73EDii
Main camera: ZWO ASI294MC-Pro
Main camera filter: IDAS NBZ Dual Band
Guidescope: AstroEssential 50/200
Guide camera: ZWO ASI174MM
Guide camera filter: Astronomik UV/IR cut
Total integration time: 5 hours
Acquisition software: ZWO AsiAir
Processing software: PixInsight – GIMP