K3's Astronomy - Deep Sky
"When I consider your heavens, the work of your fingers, the moon and the stars which You have set in place, what is Man that You are mindful of him?" -- Psalm 8:3,4

M20 - The Trifid Nebula in Sagittarius (NGC6514)

Click the image to see the full size picture (1.57"/pixel).
M20 - The Trifid Nebula in Sagittarius, 19.06.2002 (23:29 - 23:43 UT)
Resolution: 3.14 arcsec/pixel
Camera: Vesta 675SC2 + 0.6FR
Telescope: 8" F6 Orion Europa Newtonian
Result focal ratio: F3.6
Exposure: 11x25s (gain 100%), AMP OFF, 20xDF, FF
Seeing: lim.magnitude for naked eye 4.2, windy, foggy clouds, 9 days old Moon!
Temperature: 18C

1, Stacked with K3CCDTools, exported to FITS
2, Histogram (MaximDL Demo)
3, Brightness-Contrast-Intesity balance (-4;15;25) in Corel PhotoPaint
4, Result image was filtered by Neat Image

M20 is a red emission nebula surrounded by blue reflection nebula (at the northern end). Its distance is uncertain, the mean estimated value is about 5200 ly. Visual brightness is 6.3 mag.
The nebula veils a great potential for astrophoto - this photo was taken during Moon's shine 2 days after 1-st quarter Moon, while the M20 was only 17 above horizon.

After taking the first 30 frames (with 11 good frames) my telescope was limited by balcony rail. So I had to move it. After moving the field of view of camera was rotated.
a, I captured then 13 good frames and stacked them in K3CCDTools.
b, Then I stacked the above image with the second image in MaximDL Demo, which allows stacking with field rotation.
The result image contains less noise (stack of 26 images in comparison with 11 images). But the area of result image was only a part of the area of above image.

Click the image to see the full size picture (1.57"/pixel).
I cut only the central circle part of the second image and did an assembly in Corel PhotoPaint. Here is the result.

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Last Update: 23.06.2002