Sunspot Imaging – 22nd July 2016
SOURCE: SOHO – Solar and Heliospheric Observatory
It’s been so long since I have had the telescope out, I have been getting withdrawal symptoms so, while the kids were busy roller-skating, I thought I would take advantage of the bright, clear sky and try my hand at some solar imaging. I have taken a few snaps before, mostly around the eclipse last year, but haven’t tried capturing detail in sunspots, so that was the plan.
I didn’t have much time, so I just did a basic alignment of the mount and scope, centered on SOL and set the mount to solar tracking rate – which seemed to keep things central so that was good enough for me.
***NB – The images were taken with the addition of a home-made Baader White-Light Solar filter. DO NO try imaging or viewing the sun without a proper filter in place!***
I used my ZWO ASI120MM camera on the telescope to take a number of 60 second videos of sunspots 2565 and 2567. I also used a 2.25x Barlow with the camera for some additional videos to get a bit closer. The videos gave me over 4,000 frames to process, which is probably a bit much, but better to have too many than too few. Next time I might drop the length of the video though as it does take a bit longer to process larger numbers of frames. SHARPCAP was used to collect the images, using a fairly low gain and very short exposure times.
The videos were initially processed in PIPP using the Solar Close-Up and Surface Feature settings and I only kept around 10% of the best frames, leaving me with around 400 to stack. Stacking took place in AUTOSTAKKERT2 and the resulting stacked image was tweaked in REGISTAX, using the wavelets feature, before a quick trim and tidy in Photoshop. If anyone has any questions about this workflow, let me know. I should write a brief tutorial when I get more time.
Anyway, the first image below is without the Barlow in place.
and the second with the Barlow
Considering that I was rushing to take advantage of a spare hour, and that I couldn’t see the Laptop screen without holding the remains of a cardboard box over my head, I am very happy with the results and look forward to having another go when there are some more sunspots to look at.
Images are also posted in the Gallery.