The Omega Nebula, also known by various names such as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and Horseshoe Nebula, is catalogued as Messier 17 (M17) or NGC 6618. This H II region is located in the constellation Sagittarius. Discovered by Philippe Loys de Chéseaux in 1745 and later catalogued by Charles Messier in 1764, the nebula lies amidst some of the richest starfields in the Milky Way, particularly in the northern part of Sagittarius.

The Omega Nebula is situated approximately 5,000 to 6,000 light-years from Earth and spans about 15 light-years in diameter. The nebula is part of a larger cloud of interstellar matter that measures around 40 light-years across and has a mass of about 30,000 solar masses. The nebula itself has an estimated total mass of 800 solar masses.

Renowned as one of the brightest and most massive star-forming regions in our galaxy, the Omega Nebula shares a similar local geometry with the Orion Nebula, although it is observed edge-on rather than face-on.

Object: M17

Location: Portsmouth, UK

Mount: Alt Az

Bortle Scale: 7

Nights:       19th June, 13 & 15th July 2024

Total Subs Used: 279 x 10 Subs

Seeing:  Clear

Fits Stacked: Siril

Post-Processing Steps

1. GraXpert - Background extraction and Denoise v2.0 

2. Siril - colour calibration, photometric colour calibration, removing green noise, colour calibration, histogram stretch, colour saturation.

3.  Lightroom