Celestial hemisphere:  Southern  ·  Constellation: Sagittarius (Sgr)  ·  Contains:  M 20  ·  M 21  ·  NGC 6514  ·  NGC 6531  ·  Trifid Nebula
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M20 The Trifid Nebula, 



    
        

            Philip Herbst
M20 The Trifid Nebula
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M20 The Trifid Nebula

Getting plate-solving status, please wait...
M20 The Trifid Nebula, 



    
        

            Philip Herbst
M20 The Trifid Nebula
Powered byPixInsight

M20 The Trifid Nebula

Acquisition details

Dates:
June 27, 2022
Frames:
103×300(8h 35′)
Integration:
8h 35′
Avg. Moon age:
28.09 days
Avg. Moon phase:
2.33%

Basic astrometry details

Astrometry.net job: 5926597

RA center: 18h02m40s.8

DEC center: -22°5913

Pixel scale: 1.771 arcsec/pixel

Orientation: 180.487 degrees

Field radius: 1.054 degrees

Resolution: 3564x2376

File size: 11.3 MB

Locations: The Place, Ladismith, Little Karoo, South Africa, WC, South Africa

Data source: Traveller

Description

An Iconic Nebula that I have been wanting to capture for some time. Perhaps better imaged with more focal length and perhaps a reflector as I really like the diffraction spikes on other images I've seen of this nebula but I like the colourful star field nevertheless. 

An RGB image that I have enhanced with an artificial HaOIII luminance. Unfortunately had to discard the luminance due to dewing on the camera front window (visible when looking down the barrel of the telescope) causing a large central black spot. The cold ambient temperature left the ASI1600 quite idle working at less than 50% to maintain -20C sensor cooling, leaving very little excess heat to dehumidify the cover glass (ambient temperature 5-8 degrees C and humidity of 87%). This was my second such an experience. The solution was paradoxically to drop the sensor temp to -30C which made the camera work harder and the sensor  front glass condensation progressively disappeared over about 10 minutes or so. I had to retake calibration frames of course. A second solution occurred to me which I have tested in principle  which is to cover the camera loosely with a shirt. This reduces the passive environmental cooling enough to make the camera work harder to maintain the set temperature cooling. This has taught me that the passive heating of the ASI1600 cover window is perhaps not as robust as I thought it might be. I wonder whether others have had this experience and whether I should be looking for another problem.

Skywatcher Esprit 100ED
Avalon Linear FR
ASI 1600 MM Pro

​​​​​​​Total exposure 103 x 300s ~ 8.6 hrs
Bortle 3-4 skies, SQM varied in the 21.1 - 21.4 range on the night of capture. Pretty dark coming from the City.

The Place, Little Karoo, South Africa

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M20 The Trifid Nebula, 



    
        

            Philip Herbst

In these public groups

Southern Hemisphere Astro