Eastern Veil, Western Veil, Supernova and Pickering’s Triangle
I got an amazing weather this year. I’ll publish three posts in total for my days in Sardegna. Three different targets shot, after three months of horrible skies without any opportunity since the Bubble Chase.
Well, since end of May, I got one or two slots: the first one I asked for a rain check (“rain” check is funny … real reason was that I was too tired), and the second one I sadly lost hope after an hour during which the polar alignement was going nuts and then the camera didn’t want to transfer any shot to my computer …
I packed religiously (it took me 4 hours) my nomad setup, trying my best not to forget any cable or connector or Allen keys or anything else. Well, I packed well … I didn’t miss anything and that was a good start :)
Thanks to a small piece of software named Kstars (there : https://kstars.kde.org ), I created a list of objects I definitively want to catch. It has an observation planner with a wish list you can populate.
This post is about my second target. I already shot Eastern Veil (one of my first use of the Hyperstar lens), but my short focal and big camera sensor gave me the opportunity to catch the big picture and not only one nebula.
After multiple nights of shooting on the first target, I wanted to get something easy. Let me explain : this shooting was very smooth. The object has an easy magnitude (Mag 7) so it is enough bright and you’re pretty sure to get something quickly.
354 shots for lights with the HaOIII filter, I had to take care of the meridian flip (I’m thinking about automating it, I need to work on that), I took the flats and biases from my previous target sessions … I imported the shots from the mini-PC to my Macbook.
These results (with stars and starless) are dedicated to my son, and so there is a signature on them. He spent an hour (maybe more) sorting the 354 shots to get at the end the 191 good shots with well round stars.
I launched the WeightBatchPreProcessing script in PixInsight (stacking flats/biases and lights), and 4 hours later I got the stacked Masterlight picture.
Some may wonder : you have been rigorous with taking flats and biases calibration shots so why didn’t you get darks calibration shots ? Good question ! Well, usually, at my place on the continent, I get the biases and darks shots from inside the house (warm and cosy, still I activate the cooling to get the same temperature than my lights) while I’m sleeping (so in the dark). This time, I launched the biases and darks in the morning while I was importing my light shots … and my first stack process gave me an horrible result … after a couple of tries (took 3 of them, 4 hours long each …), I figured that my darks shots got vignetting with various colors on each shot … I think that because the darks were exposed for 45/60seconds, and it was daytime, natural light was probably hitting the sensor by behind (the radiator in the back of the camera). When I stacked without the darks, the result was correct …
Initially, I thought I would go for SHO palette, but the result I got with only the HaOIII filter was really more than good enough so I saved a night for another target ;)
You can see on the Exif below that the Guiding System is crossed out … unfortunately I couldn’t use it for a reason I will explain in the next post. Hint : you need to have some basic electricity knowledge.
Exifs : Askar FRA300 + PegasusAstro Nyx-101 + PlayerOne Poseidon C Pro cooled at 0°C / Askar Duo Magic D1 filter 2” Halpha/OIII - Guiding System Askar FMA135 with PlayerOne Ceres C
354 lights 45 seconds each - 191 selected for stacking
50 flats Gain 120 filter D1
50 biases Gain 120
Stacked with Pixinsight (WBPP)- Post-Treatment with Pixinsight: Delinear and AutoHistogram (really that’s it!)
