NGC3247 and IC2602

Maybe not as much of a “wall of text” this time… Maybe.

I went up to the LMDSS for Australia Day, as the cloud forecast was for clear skies. It helped that I had taken the next day (a Friday) off work to make a very long weekend. Sadly, I wasn’t able to stay for Friday night - and it was forecast to have clear skies as well.

I had both rigs out that night - the Star Adventurer was taking 50-image series of various parts of the night sky. I don’t know what I’ll do with them yet, but I’m certain they’ll be used for something. Eventually. Maybe another astro-landscape or something.

I’d selected a few targets for the big rig, and eventually settled on NGC3247, also known as “The Whirling Dervish Nebula”. I collected 4 hours worth of data on it - 2 hours of Ha/O3 via the L-Enhance filter, and 2 hours of UV-IR cut data. The sad part is that I over-exposed the UV-IR subs. 120 seconds was just too long, and I ended up with an image that is a spray of over-exposed, blown-out stars that totally over-power any of the faint nebulosity. Well, now I know for next time!

By the time I’d captured the NGC3247 data, it was about 3am and most of the others on the astro field had packed up and gone to get some sleep. Me, I chose another target (IC2602 - The Southern Pleiades) on a whim and was about to kick off a 2-hour imaging run when I realised that I’d run out of darkness! So I had to drop it back to 1 hour of data. When that finished, I cued up a session to capture some Dark frames and crawled off to get some sleep a bit after 4am.

I tried stacking the two data sets for NGC3247 and then combining them as layers, but it looked awful. I tried using starnet++ to strip out the stars and create two layers of only the nebula data but that looked awful as well. So I went with just stacking and processing the L-Enhance data and ran with that.

When it came to IC2602, I used both Affinity Photo and SiriL to give me two views of the data. I can’t decide whether I like the image with the brighter starrier background, or the darker background. (As for the diffraction spikes I’ve found that I prefer the stars to have them when it’s a smaller, more open cluster such as this. To my mind, the stars just don’t look “right”.)

IC2602 Image details:

• Gain: 100
• Offset: 10
• Temperature: 0 degrees C
• Exposure: 120 seconds
• Lights: 30 (1 hour of data)
• Darks: 25
• Flats: 0
• Dark Flats (Bias): 0
• Filter: UV/IR Cut
• Stacked and proc’d in Affinity Photo and SiriL

NGC3247 Image details:

• Gain: 100
• Offset: 10
• Temperature: 0 degrees C
• Exposure: 120 seconds
• Lights: 60 (2 hours of data)
• Darks: 50
• Flats: 0
• Dark Flats (Bias): 0
• Filter: L-Enhance
• Stacked and proc’d in Affinity Photo

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• Astro