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M20 - The Trifid Nebula |
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Also known as NGC 6514, this emission nebula (red) surrounded by reflection nebula (blue) is found in the constellation Sagittarius (the Archer). It has a magnitude of 6.3 and a size of 29.0 arc-minutes. It sits at a distance of about 5000 light years.

The above image is an LRGB composite taken at f/6.3 on the 12" LX200 and ST-8E. Ten 1 minute 2x2 binned luminance, seven 1 minute 2x2 binned red, seven 1 minute 2x2 binned green, nine 1 minute 2x2 binned blue, ten 1 minute 3x3 binned blue. All exposures were unguided.
Color balance was tricky. At a sky altitude of 23°, extinction gives ratios of 1.00 : 1.13 : 1.25. My CCD color sensitivity requires a ratio of 1.00 : 0.88 : 1.82. The result is 1.00 : 0.99 : 2.28.
Taken at the ARGO site on 7/1/2000.
Previous color attempt:
This
is an LRGB image. The Trifid is the reddish area at the bottom. The
original intent was a color mosaic. It was never finished because the
color data seemed too crummy. However the test shot with no filters was
OK, so I later merged the crummy RGB in by doing an aggressive low pass filter
on it, but leaving the test shot alone as the luminance data.
L, R and G are all 2 minutes. B is 3 two minute shots. All were at
f/6.3 with the 12" LX200 and Meade 416XT. August 13, 1999 at the
Table Mountain Star Party.
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Aug 28, 1997 at the 1997 Oregon Star Party
On the first night of the OSP everyone around me seemed to be looking at this object so I figured I'd give it a go. The next night I studied the Trifid visually, and compared it to a view in a 20" Dobsonian. The Dob was brighter (Duh), but the 12" held its own in contrast and detail.
A 20 second exposure taken with the 416 at f/3.3.
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