One of the surface features of Jupiter which I have been interested in imaging is the Great Red Spot. On the night of 21/5/15 the skies were very clear with hardly any cloud. Hence even though I was working the next day, I decided not to waste the opportunity and set up my telescope to image Jupiter. I knew that from 21:48 Hrs of that night, the Great Red Spot would be visible. So I brought my telescope out 2+ hours before to let the mirror cool down sufficiently.
Now while the skies were clear, the seeing was not brillliant. I could tell as it was actually difficult to decide when Jupiter was sharply in focus. But I made do with what I had.
Orion Optics VX12 12″ Newtonian reflector, Celestron CGEM mount, Celestron Neximage 5 imaging camera, Televue 5x Powermate, Baader Neodymium filter and Microsoft Surface Pro 3 laptop.
Celestron iCap to capture the video for processing, PIPP to preprocess (debayer and center) the image, Autostakkert 2 for stacking and Registax 6 for wavelet application.
From what I’ve read online, it looks like some have had success with the Neximage 5 with Gain set at 20 and exposure at 1/60 secs for an F10 telescope. Hence with my setup, as my telescope aperture is F4 and I’m using a 5x Powermate with this, I decided to use a setting of Gain 20 Exposure 1/30. I did use 2x binning to increase the frame rate of capture, as it was clear the seeing would not support capture all full resolution. The frame rate of capture was about 21 frames per second. I used Y800 to capture the AVI as this reduces the file size to 1/3 of the RGB32 file, and also for some reason allowed me to get better stacking results. I did the debayering with the PIPP prior to processing in Autostakkert 2.
Previously I had been using Registax 6 for stacking, but having read about Autostakkert 2, I decided to give it a go. The great feature about this program is that it has a quality graph analysis to let you know how good the quality of the frames captured are. This allows me to decide what percentage of frames I can stack to produce the final image in Tiff file format. Then the image is processed with wavelet to get the final image. As can be seen, the images I’ve captured are seeing-limited but does capture the Great Red Spot well.
As I had about 10 frames captured, I thought I would stack them together to produce an animated GIF.
Now the question is whether the Great Red Spot is indeed red in colour, and the answer is a definite yes. I am hoping there will be even better opportunities to capture the details of Jupiter when the seeing is better, which will be when it is higher in the sky.