M20 - The Trifid Nebula
Description: M20, the Trifid Nebula, is located in the constellation of Sagittarius. This image was taken on July 4, 2008 at the Golden State Star Party near Adin in northeastern California. The sky conditions at the time the image was taken were not ideal. The object was low on the southern horizon in an area obscured by smoke and haze from rampant wildfires to the south and west. Because of this, the colors are not very accurate. The emission portion of the nebula should be more red, and the reflection portion should be more blue. Also, I had some guiding difficulty due to the seeing conditions and was seeing guiding errors approaching plus or minus 1 full arcsecond. Because of this, the image is not as sharp as it should be.
Equipment: The image was taken with an 8" Meade LX200ACF telescope on a Celestron CGE mount. The camera was an SBIG ST10XME with an Astro-Physics .67 Telecompressor and Astrodon filters. The guide scope and camera were an Orion ST-80 refractor with an SBIG remote guide head attached to the ST10. Focusing was done with an Optec TCF-S focuser with temperature compensation turned off.
Exposures: 13x60 seconds luminance binned 1x1; 9x60 seconds red, 6x60 seconds green, 6x60 seconds blue exposures binned 2x2.
Processing: Bias, dark & flat calibration, image registration & color registration were done in Maxim/DL. Curves, levels, LRGB combination, zone sharpening & noise reduction were done in Photoshop CS2. Gradient processing was done with GradientXTerminator.
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