Jupiter and Saturn: Quality Jumps


by Philip Steffey with Matt Allard

In January and February, 2003, we obtained video images of Saturn and Jupiter for the first time with the 14-inch Celestron telescope at Bethune-Cookman College, using an Orion 'color electronic eyepiece' and a 13-inch TV monitor.  The images were promising but video recordings made therefrom refused to yield acceptable still pictures.  In early 2004, using a newer, battery-powered Orion camera, we obtained videotapes providing stills as well as computer-captured images of the two planets; but the images were mediocre even with good 'seeing' and the telescope behaving itself.  An account of these efforts are at the B-CC Observatory website.
As I was applying improved image-processing skills, with Photoshop, to the 2004 videography, we had an order in to Polaris Industries for a DX-8263SL camera, which has twice the spatial resolution of the Orion camera, integrating capability up to 2 seconds, and several other new features.  It arrived in May and I shifted to learning to use it, which required deciphering  Pidgen English and numerous acronyms in the short instruction manual.  (I'm still struggling with some of this material.)  The solar transit of Venus in early June distracted us (no objections!), but on the 18th we obtained Polaris video images and taped (VHS) recordings of Jupiter, rather low in a murky western sky soon after dusk.  The live images were decidedly the best to date and yielded pretty good stills; see the first set following this text.  The large picture is from images enlarged with the camera's digital zoom.  We knew that a clearer, darker sky, smarter use of the camera, and better imaging and recording facilities (e.g. S-video camera output, computer intake) would give better results.   But for Jupiter, and Saturn, this would have to wait until the beginning of 2005.
The payoff was slow, due we believe, to telescope problems --mainly corrector plate dewing-- and incorrect camera settings, but on March 5 we obtained good images of Saturn and inner moons including Enceladus.  A raw still of the planet and a processed picture from a manual stack of frames are reproduced in the second set following this text, and a third graphic shows the moons.  On April 22 we had another good session with this planet; the fourth graphic below compares processed stacks of 8 still frames from this and the March 5 session.  For all of these observations we connected the camera's output to the observatory's PowerMac computer and displayed the images with the Apple Video Player.  Some still frames were captured using Flash-It, and short video 'strips' were made as well so we could get numerous high-quality frames.    
Jupiter had moved to western Virgo and wasn't well up in the evening sky until the spring of 2005.  Our first good observation of the planet came on May 6 and was a winner.  The Great Red Spot was conspicuous near the central meridian, and we watched and recorded its positions for two hours as it approached the 'off' limb.  Processed stills from the computer-captured video are shown in the last picture set below.  The middle picture approaches the quality of many, made with similar equipment and level of processing, published in the popular astronomy literature. The Saturn pictures are close too.  We have a way to go but we know how to get there.

Notes  to  Pictures

Saturn's moons:  Enceladus's image is so strong on raw frames, at less than maximum camera sensitivity, that getting Mimas at greatest elongation and in a very good sky, appears feasible.

Jupiter on 6/18/04:  The oval dark spot on the south equatorial belt, approaching the central meridian, was variable in structure and contrast in raw images.  Some had several tiny black spots around the oval's periphery, others only two or three, some none.  But pixel flaws are present so I cannot claim this phenomenon was real Jovian activity in a period of under 20 minutes.



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