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With the possible exception of the Eta Carinae Nebula, M42 is the finest example of an emission nebula in the sky, visible to the naked eye even from moderately light-polluted locations. It is about 30 light-years in diameter and is about 1,600 light-years from the solar system. At the heart of the nebula is the Trapezium, a beautiful multiple star visible in small telescopes. The entire nebula is a region of star formation; the open star cluster associated with the nebula is only about 500,000 years old, one of the youngest known. The central portion of the nebula is bright enough to activate the color receptors in the retina when viewed in moderate to large aperture telescopes. Observers have been able to detect greens, yellows, and reds in this portion of the nebula, although I have been able to detect only greenish color with my 14.5" scope. The "backwards comma" shaped region at the lower portion of the nebula has its own Messier number, M43. NGC 1977 is the blue reflection nebula on the left side of the image. It is sometimes called the Running Man Nebula because of the distinctive dust pattern which resembles the profile of a running person (you may need to tilt your head toward your left shoulder to recognize it).

Equipment: ST-10XME/Vixen 102-ED/G-11
F-ratio: f/6.5
Exposures: LRGB: L 8 x 3 min: R 8 x 3 min: G 8 x 3 min: B 8 x 3 min: RGB binned 2x2. Trapezium LRGB: L 8 x 10 sec: R 8 x 10 sec: G 8 x 10 sec: B 8 x 10 sec: RGB binned 2x2.
Date: December 10, 2004
Location: Landers, California, USA
Technical Notes: Individual exposures were acquired using CCDAutoPilot and were sigma combined. The RGB images were created in Registar 1.0. Unsharp Mask of 2 pixels with Threshold of 0 was applied at 100% to the luminance image. A Gaussian Blur of 1 pixel was applied to the dim portions of the luminance image and to the RGB image. A blurred copy of the luminance image was used to create an unsharp mask, which was subtracted from the original. The Trapezium image was pasted into the main image using a Selection Layer.