The Swan Nebula is an HII region, with a 6.0 apparent magnitude, that lies around 5 to 6 thousand light-years away in the rich starfields of the Sagittarius area of the Milky Way in the constellation Sagittarius. Phillippe Loys de Cheseaux discovered this nebula in 1745 and it was catalogued in 1764 by Charles Messier. Considered one of the brightest and most massive star-forming regions in our galaxy, this nebula spans some 15 light-years in diameter and has a total mass estimated to be 800 solar masses.
Other designations: M17, Messier 17, NGC 6618, Sharpless 45, Omega Nebula, Checkmark Nebula, Lobster Nebula, Horseshoe Nebula, Gum 81, and RCW 160.
Telescope: Sky Watcher Quantum 120 Apo @ f/7
Accessories: SW Quantum matched flattener; Dew control by Dew Buster; Alnitak Flat-Man
Mount: Takahashi EM-200 Temma2
Camera: QSI583wsg CCD @ -10.0C
Guiding: Starlight Xpress Lodestar via PHD
Filters: Astrodon Tru-Balance E-Series Gen II LRGB filters
Exposure: 18 x 10 min. binned 1x1 Luminance; 14 x 5 min. binned 2x2 in each R, G, & B
Acquisition: ImagesPlus 5.0 Camera Control
Processing: PixInsight 1.8; Adobe PhotoShop CS5
Date(s): July 4 & 5, 2014
SQM reading (begin - end): N1:18.74 – 21.17; N2:18.81 – 20.61
Temperature (begin - end): N1:65.8ºF – 59.0ºF; N2:66.6ºF – 61.3ºF
Capture conditions: N1 - transparency: Above Avg 4/5; seeing: Above Avg 4/5; N2 - transparency: Above Avg 4/5; seeing: Above Avg 4/5
Location: Natchez Trace State Park, Pin Oak Lake RV Campground, Wildersville/Lexington, TN, USA