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messier 42

 

Visible even to the unaided eye, the Great Orion Nebula is without a doubt one of the grandest spectacles of the entire sky. Located in the sword of Orion, M 42 is a splendid example of an HII region, an emission type nebula composed of mostly hydrogen being ionized by ultraviolet radiation from one or more hot young stars. Despite appearances, the Orion Nebula is but a very small "visible" blister on the face of a much larger cloud of gas and dust known as the Orion OB1 star forming region. This immense cloud of mostly "invisible" material has been mapped out in extensive detail using infrared and radio telescopes, and it is now known to cover the majority of the constellation that we know of as Orion. The brightest portion of this image represents the point at which the highest levels of ionization occur and is home to a small group of young stars that are responsible for this wonderful object. Several other notable objects within this field of view include the bright reflection nebula NGC 1975 just north of M42, the bluish IC 420 to the upper right, VdB 42 to the lower right, Wolf's Smoke Ring to the far left of center, and the ruddy Simeis 144 to the upper left. Image taken with 4-inch f/5 refractor and SBIG STL-11000XM. LRGB composed of 60 minutes each R,G,B and synthetic L channel. Click on the image above for the high resolution version.