First, a bit of housekeeping. I have not been posting a lot this month, but that does not mean I have not been stargazing. On the contrary, the amazing weather my area has had for the last few weeks led me to take advantage of it as much as I can. For example, this week I did a triple feature with my telescope: first imaged Jupiter, then did some DSO searching, and finished with Saturn imaging. All under a clear new Moon sky. When I do take pictures, I try to push them to my Twitter account, just because it’s the faster way to post them.
And speaking of housekeeping, this post is a much delayed matter I finally got around too. On May 31st I took a good sample set of Jupiter images to attempt an animated GIF. I shot five video sets all about 15 minutes apart. The above is Jupiter alone. As you can tell, I do not have an equatorial mount, so Jupiter was in process of still ascending into the night sky at the time I took the videos.
While the planet came out pretty well, unfortunately this was a terrible time to include the Galilean moons. The only one that was reasonable close was Io. And bad for Io, it was at the edge of its orbit perpendicular to Earth, so over the course of that hour, it appears to have hardly moved. See for yourself:
Obviously this second animated GIF is overexposed in order to show Io. Given that I do not have an equatorial mount, I doubt I will be attempting this animation exercise next Jupiter season, preferring to focus on observing, still photography, and sketching. If anything, I now know the approximate radius of Io’s orbit through the telescope. Still, I am glad I attempted this exercise as it is one more achievement to cross off my astronomy to-do list.
On the night of May 16th, despite high winds I attempted to put together a sequence of Jupiter images to make an animation. I took video approximately every 20 minutes for six capture sessions in total.
The above animation is only showing two of those six final images. Problems with the others were different light intensities and increasing cloud cover. For reference, here are the first five images so you an see what they look like. The above animated GIF was taken from the second and third images. The sixth image is not shown because it was simply garbage due to the clouds by that time.
The sky was by far the clearest during the first capture session.
Oh look above, there is Ganymede! It just popped out from behind Jupiter!
You can see the quality of this final image is noticeably degraded from the prior four, due to the encroaching clouds, which made the sixth session unusable. Also observe that Ganymede moved a little to the left across the 20 minutes from the fourth image.
(And in case you are wondering, at this time Callisto was way to the right of Jupiter.)
Putting together this animated GIF was mostly an accident turned prototype. I had planned to try making Jupiter animations once I felt reasonably confident with my digital camera. But I noticed after Monday night’s session, which happened to capture Io as it was about to pass behind Jupiter, that I had roughly 12 minutes of video on Jupiter, somewhat evenly spaced. So here is the end result.
I used different gammas, which causes a couple of the frames to be brighter. If I wanted to make a clean GIF I would have uniformly set the gamma. Also, I discovered that centering the image is very tricky, and will likely be the hardest part of the process when I try to string together an hour or two of footage. Maybe I will figure out a shortcut on these cloudy and rainy nights.