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Trifid Nebula M20



Scope: Celestron 9.25 Edge 235 mm at f/7, Location: Tierra Del Sol (SDAA Club site), CA  6 July 2013  Camera: ST8300M

Exposure: 10 x 8 min  (1x1 bin) exposure with UV/IR block, 10 x 6 min (2x2 bin) Hydrogen Alpha exposure, 8 x 3 min (2x2 bin) RGB exposures.

Processing: Data Collection -  CCDSoft (as FITs).  Calibrated, stacked (Sigma Combine), LRGB channel registration, central gradient removal, and color equalization - Astroart.  Curves, Levels, LRGB combine and finishing  - Photoshop.  Color calibration using eXcalibrator. This image is a HaL-RGB combine with Luminance layering -   Final Image size is approximately 2400x1800.

North is up in this image.  M20 is a frequently imaged and popular object for observation. This image uses a narrowband HA exposure to add contrast to the red hues. M20 is a combined emission (red) and reflection (blue) nebula in the constellation of Sagittarius. M<20 has other catalog designations as well - it is also known as Sharpless 30 and LBN 27. The prominent dark lane in the emission nebula is known as Barnard 85. M20's distance is not precisely known. Estimates range from 2,200 to 7,600 light years. This image replaces an earlier image that can be seen in the Archives here.  The Horizontal FOV is 38'.

Image center is located approximately - Equatorial 2000: RA: 18h 02m 16s Dec: -2258'22


All images and content remain the property of Jim Thommes - copyright 2003 - 2013

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