UPDATED - NGC 6188 - The Fighting Dragons of Ara
My latest image is probably one of the most imaged nebulae in the southern skies after the ‘big ones’ of Eta Carina, The Running Chicken and Rho Ophiuchi. I’m not putting the Orion Nebula in this list because that’s primarily a Northern Hemisphere sight, and we’re limited to a couple of months where it’s visible. I think just about every astophotographer will image this one at least once, simply because it’s such a fantastic sight to behold.
The official designation is ‘NGC 6188, an emission nebula in the constellation of Ara’, which is pretty boring when compared to the common name of ‘The Fighting Dragons of Ara’.
Stretching across more than 600 light-years of space, these massive clouds of dust and gas are home to various star-forming areas, as well as a cluster of massive, young stars. The intense light and radiation from these stars carve shapes into the gas and dust clouds. The light from these stars and the energised gas takes about 4000 years to reach Earth.
How did this nebula get it’s catchy name? It’s kind of obvious when you look at it - the dark tendrils of dust look like two giant dragons in endless combat, silhouetted against the red emission from the clouds of energised Hydrogen gas.
I captured this data last Friday night (taking advantage of the first clear night in over a month!) from my backyard here in suburban Melbourne.
I won’t go into all the hassles I had getting started - it took over an hour of fiddling around with software problems and camera rotation (including reassembling the optical train multiple times with different thickness shims before the camera was at the right angle).
All the struggle was worth it, as the end result is what I feel is my best image yet. So much so that I got it printed at A1 size and it’s now at the picture framing shop getting put behind glass. Then it will be put up on the wall.
The portrait image is the entire scene from the camera, showing a large amount of the nebula; whilst the landscape image is a crop of the central region to concentrate on the ‘dragons’.
In terms of processing, the ‘Starnet++’ tool is amazing - I was able to remove the stars from the image, process the nebula to bring out detail and get it how I wanted it, then process the stars separately and finally mix the two layers together.
Image data:
- Gain: 100
- Offset: 10
- Temperature: 0 degrees C
- Exposure: 120 seconds
- Frames: 120 Lights, 25 Darks, 50 each of Flats and DarkFlats (4 hours integration in total)
- Filter: L-Enhance (Ha + Oiii dual-narrowband)
- Processed with SiriL (stacking and pre-processing) then finished in Affinity Photo v2
Equipment: SW72ED @ 357mm / HEQ5-Pro / ASI183MC-Pro / SV165+SV305 / Kstars/Ekos
Update - 06-07-2023
I recently started watching more YouTube videos about the SiriL program (which you have all read me rambling about) and stumbled across the @DeepSpaceAstro channel, hosted by Rich.
He has a short playlist (only 3 videos at present) about custom SiriL scripts that he has written. One of these scripts converts a stacked image into the famous ‘Hubble’ false-colour palette.
I felt it was worth a try, so dropped my stacked and unprocessed Dragons image into it to see what I’d get out. The image below has almost no post-processing done to it - I’ve saturated the colours, done a noise-removal filter and nothing else. I’m quite impressed with how it’s come out and I can’t wait to try this script on other targets.
Compared to the image above, there is a lot more contrast between the dragons and the dark dust clouds. Note that I did not do any star removal, so they’re all a lot more visible than the image above.