An imaging session of Jupiter on Tuesday evening 2016 April 26 EDT, April 26/27 UT

Sometimes it gets confusing, but all of the images are annotated in UT time, to more easily compare with others’ images.

Tuesday night was interesting to say the least. First clear night since I got the autoguiding to work properly.

I was able to start imaging Jupiter before sunset.
Mainly I did it just to see how it would turn out… I was not expecting a lot at all. And that’s what I got!
One of the first things to notice is the initial images colour balance. The background sky was quite blue and when you run that through registax autobalance RGB, it really changes for the worse. You can see this in the attached .mpg file

The air/seeing was also very turbulent, showing that we really need to wait until well after sunset and let the atmosphere cool and calm down.
I will probably wait a little later in the future.

Focus was difficult as well. Have to work on methods to achieve initial focus and then on changing it over the course of the night.
The remote ascom based focus control is not working well. One mouse click right, focus increments by one. one mouse click left, focus increments by -10. No amount of configuration seems to make it work well. Will have to experiment more.
60 runs were attempted, 54 runs were usable.
Exposures at the end were approx 33ms, less at the beginning (25ms?) because of the sky brightness.
Average frames per second was about 29.

The first run was 19:45 EDT and the last at 21:30 EDT, or just under 2 hours.

These sequences used the best 50% of each image run and this was the best image of the entire night, taken at 20:47 EDT.
I’ve settled into 90 second exposures with a 30 second break for Jupiter, so 60 runs would be 2 hours normally.
Each 90 second run gave approx 2600 images.
Jupiter’s apparent diameter is now 41.20 arcseconds
The ZWO ASI 120MC camera is Not cooled and the sensor temp was 8C (looking forward to getting a cooled camera in the future).

The region of interest that I am using has been shrunk a bit, down to 450×450, as the autoguiding is so good. That means smaller file sizes for the .AVI’s, less stress on the USB2 bus trying to move more data faster, and may actually allow for a slightly higher frames per second