| M17, NGC6618 Swan Nebula (aka Omega, Horseshoe, Checkmark or Lobster Nebula) Constellation: Sagittarius (The Archer), Equatorial 2000: RA: 18h 20m 48s Dec: -16°11'00" Distance: 5,500 light years, Visual Magnitude: 6.00, Diameter: 20 x 15 arc mins, 15 light years Transits at the end of twilight at 7:25pm 9th September, elevation 74 degrees, due North |
| - Imaged on 20090725 - 25cm 10" F/4.7 Newtonian Reflector - 300 video frames with IR/UV blocking filter at x128 integration - Bahtinov focusing mask - rough polar alignment, crescent waxing moon, poor seeing, elevation about 60 degrees - aligned, stacked and sharpened in Registax - levels adjusted in Photoshop 7.0 |