I took my new 9.25″ SCT to the RRO last night for my first attempt at imaging with it and my first attempt at Saturn in a long time. The results are encouraging. The image below is the best 20% of 1000 frames of 40 milliseconds each (click for larger view). I have checked the collimation of the scope each time I’ve taken it out but have not felt a need to adjust it. The out of focus star could be used as an image of how it should be.
I do need to work on a few things. My tracking has been off lately, I think a mount setting got changed and I just need to get the manual out and review. I also need to get or make a dew shield, maybe a focusing mask.
Wednesday evening, during a rare clear night in May, I was able to capture this sequence of events happening on Jupiter. At the very start you can see Jupiter’s moon Ganymede over to the left and its shadow on the face of the planet. Almost immediately you will see the shadow of another moon, Io, appear on the right and start chasing the shadow of Ganymede. Each frame represents 2 minutes of real time and the entire sequence is an hour and 40 minutes long. As you watch, you will also notice the Great Red Spot moving along with the shadows and if you look closely you might notice Io itself transiting the disk of Jupiter but it is not nearly as obvious as the shadow. You might also notice the difference in the size of the shadows. Ganymede is the most massive moon in the solar system while Io is quite a bit smaller. Eventually Io leaves the disk and becomes visible against the black background. Finally at the end the two shadows merge as Ganymede eclipses Io. Jupiter was dropping into the trees as this happened so I was not able to capture the end of the eclipse when the two shadows separated. I want to thank my friend Carl Freyaldenhoven for bringing this event to my attention. The images were taken from my backyard in West Little Rock.
What we have here is first a single image of Jupiter from Friday evening followed by a short video. This video shows the rotation of Jupiter over about a 20 minute time frame. I had probably another 10 minutes worth but the seeing got worse. If the motion is not immediately evident, click on it. Each frame is about 30 seconds apart.
I do need to work on a few things. My tracking has been off lately, I think a mount setting got changed and I just need to get the manual out and review. I also need to get or make a dew shield, maybe a focusing mask.
