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Catalogue and alternative designations M17, Swan Nebula, Omega nebula, NGC 6618


Type Bright nebula
Position 18 20 26, -16 10 36
Constellation Sagittarius
Camera and Telescope STXL6303 and 36.8 cm RCOS Ritchey Chretien 
Focal Ratio F9
Exposure Details LRGB image using Astrodon Near Infrared filters.  Luminance = 100 minutes, Red = Green = Blue = 60 minutes. Luminance unbinned, colours binned 2x2

With the Astrodon filters (not sold anymore), Red is assigned to a band peaking at about 850nm, Green peaking at about 830nm and Blue at 750nm.  The luminance is "visible blocked" with zero response shorter than 700nm.

Description M17 is one of the brightest and most detailed emission nebulae in the sky with the brightest portions being roughly 15' x 3'.  The entire nebula, however, spans 46' x 37' and is estimated to be about 5868 light years distant. This near infrared view reduces the nebulosity allowing many of the obscured stars to shine through.