The Dutch Observatory

Had to make use of the clear skies and image Jupiter.  Here Jupiter on November 6th.

Tonight Jupiter’s moons would be subject to another mutual event and my intentions were to try to capture some “bigger” moons this time.  The moon Io would be occulted by Europa with a total relative intensity drop of 40%.  Altough it was clear, the weather was pretty bad for observing and imaging with the image blowing all over the chip.  I did not realize that Io was not visible to start with, because it was in Jupiter’s shadow.  So I was questioning myself if the event would take place.  I started recording anyway, because I was setup .  To my big surprise, Io all of a sudden started shining a few minutes before the event and I did complete observing and recording the event despite the bad seeing.  After the fact, it would have been better to image this at f/15 rather than f/30 so the images would have been less blurry.  But I was happy to have observed and imaged my 4th mutual event this apparation!  Click the image to activate the animation!

The sky was clear again, and I am taking every opportunity to image.  Here is Jupiter with Io transitting the CM just before Jupiter disappeared in the trees to the West. 

The nice weater continued and conditions to observe Jupiter were great!  I made 5 images of which this one is the first.  I also did some more testing with the sample ratio for my imaging.  Most images I make are made with the Williams Optics 2x barlow used in binos, which result in an f-ratio or f/15.  Using the Celestron 2x shorty plus with my extension tubes allows me to go up to f/30, but at a far increased exposure time and the result is not as nice.  This image shows the GRS just sliding off the side and Ganymede getting ready to disappear behind the planetary disk.

After 9 days of clouds and rain, the sky broke open a little.  However, I could see the cloud cover to the west and south.  But it was OK for the time it took me to image Jupiter again.  Conditions were still very humid, with transparency around 4/10 and seeing 5/10.  Here one of the 5 images from Thursday evening with Io just starting its transit.

Today was a busy day with the chapter doing an outreach program for the Children School of Atlanta at Charlie Elliott Wildlife Center.  The seeing and transparancy were great but with a very high humidity, which required me to use my “hairblower” on the corrector plate several times to keep it from dewing over.  So I took the opportunity to finish the event making an image of Jupiter with the GRS.  Here Jupiter with the GRS and Europa.  Notice how the channel around the GRS has broken into the SEB.  I wonder how this will develop.

I did finish the animation sequence of 1 1/4 hour of rotation of the planet.  I had to stop imaging because Jupiter started to get behind the trees that obstruct my view of the Western sky.  So here the animation.  Visible is also Io as it approaches the planet and starts its transit.  (Click the thumbnail to start the sequence.)

The seeing conditions finally turned in our favour and we had some great seeing and transparency.  I made a series of 9 images and am working on a 1 1/4 hour rotation animation which I will publish when I am satisfied with the result.  In the meantime here one of the images.  The image shows Io while it is starting its transit accross the planetary disk.

Tonight was the night with the best seeing conditions of the year so far.  Transparency and seeing was well above normal altough it could have been better.  I made imags over a period of 45 minutes with the Williams Optics barlow.  these images have been used in the animation (middle thumbnail).  Two of them are shown as individual composites (bottom two thumbnails).  I than made two images using the Celestron 2x barlow, which gives a longer focal ratio.  I had to stop the exposure speed to 1/19 sec. and limit the number of frames to have sufficient light for a good histogram and to limit the rotation blur of the planet (top thumbnail)

Here the images from the evening of September 30th,  (October 1 UT) 

Here Jupiter with the GRS on September 29th.   Conditions were better than average with humidity and temperature being very pleasant.