M17 (NGC6618) is an emission nebulosity in the constellation Sagittarius. Its distance is estimated in 5500 light years, and of consequence its extent is 40 light years. For its shape is better known as Omega Nebula, Horseshoe Nebula or Swan Nebula. An open cluster of about 40 stars is embedded in M17, and is responsible of the emission of the hydrogen and of the red color of the nebula itself.
- Exposure : two 35 min. negatives scanned with Polaroid Sprintscan 35+, blended in Picture Window 2.0 and enhanced with Photoshop 4.0
- Telescope : Takahashi FS-102 at F/6 with focal reducer on a Losmandy G11
- Guiding : ST4 on a Vixen 80/910mm.
- Film : unhypered Kodak Multispeed PJM-2
- Location : Piano di Nivolet (Val d'Aosta) - 2600mt. height
- Date : July 16, 1999