AstroPhotography by Dan Richey

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M20 / M21
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M20 / M21

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The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is an H II region located in Sagittarius. It was discovered by Charles Messier on June 5, 1764. Its name means 'divided into three lobes'. The object is an unusual combination of an open cluster of stars; an emission nebula (the lower, red portion), a reflection nebula (the upper, blue portion) and a dark nebula (the apparent 'gaps' within the emission nebula that cause the trifurcated appearance; these are also designated Barnard 85). Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers.

Object Information

Name M20 / M21
Type Relection/Emission Nebula
Constellation Saggittarius
Catalogue NGC 6514

Acquisition / Processing

Exposure L - 20 x 300 sec Bin 1
R, G & B - each 10 x 300 sec Bin 1
Total 4.2 Hr
Telescope AP 160 - TCC f5.7
Camera SBIG STT-8300
Camera Temp -40ÂșC
Guiding STT-8300 Internal
Mount AP 1100 GTO
Filters Astrodon - Gen 2 LRGB
Processing PixInsight
Location San Pedro Creek
Date September 5, 2019

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