This emission nebula was discovered in 1745 or 1746 by Philippe Loys de Chésaux, and independently rediscovered in 1764 by Charles Messier. It lies about 5,000 to 6,000 light years from earth, and appears in the constellation Sagittarius. At visual magnitude 6, M17 is on the edge of naked eye visibility under very dark skies.

This image is a combination of 35 three minute exposures and 30 four minute exposures made at ISO 400 with a Canon Digital Rebel XT, on the nights of June 16 and June 17, 2012. The exposures were acquired with BackyardEOS software, and combined, along with flat and dark frames, using PixInsight software. The camera was attached without a lens at the prime focus of a 203mm (8") f/4.9 newtonian reflector. The telescope was controlled using Cartes du Ciel software through the EQMOD ASCOM driver, and the exposures were guided using PHD Guiding software, through a Meade DSI-C camera attached to a separate 80mm f/11 refractor.