Saturn Surprises

 by Philip Steffey and Matt Allard


    Following our observations mainly of Saturn in early 2007, we did  little more with the Bethune-Cookman 14-inch telescope for three years.  Matt left his job at the school for other employment, so we no longer had easy access to the observatory.  We came to depend on Professor Narsing Rao for admission, and he understandably was available only occasionally.  But we had other problems.

    Our equipment  and methods for capturing and recording electronic images had reached the point of no-more-improvement, at least with the telescope’s tracking irregularities and the poor sky conditions we often experienced.  Videotaping  CCD-camera images yielded a huge number of frames that were exhausting to examine visually for a few good ones worth processing, and no more than four to eight of the latter could be stacked one by one.  Also, Phil’s TV+VCR unit recorded images from its TV display, which added TV noise to other sources.  Using a computer to image the camera output created different problems, notably dependence on the old Apple Video Player and an older copy of Avid Videoshop that was missing some image adjustments--both players needing to be run on older Power MacIntosh computers.

    During 2008 we considered trying to capture and record images with a computer running a version of the Windows operating system and hopefully having  better video-handling  software than we had been using.  This change proved laborious and frustrating, resulting in a few forgettable sessions at the B-CU observatory from late ‘08 to almost the middle of 2009. A Hauppauge USB Live device and video card failed repeatedly with two versions of WinTV to display an image relayed from the Polaris camera.  We started using the VLC Media Player, which is a multi-platform application, which we were using on a Windows PC.  Unfortunately, the night sky conditions were lousy.  Our best image of Saturn in 2009, with its rings nearly edge-on, obtained in May, had to be heavily Photoshop-processed to be recognizable.  A copy is shown in Figure 1.  Uncertain at the time whether the new imaging system was contributing to the poor images, we skipped trying Jupiter during the summer, when it was near the bottom of the Zodiac.  Early 2010 offered the prospect of better sky conditions, and Mars would come to opposition, albeit a poor one.

    In the evening of February 20, 2010 we had an opportunity to observe Mars, three weeks after its opposition and with an angular diameter of 13 arc-seconds, about half that reached during the 2003 opposition.  The sky was clear but the outdoor temperature was abnormally low for the date, so the Science Building’s heat was on high and the warmed air rose into the cold just outside the observatory dome.  The “seeing” was accordingly so bad that focusing Mars’ image was only marginally possible.  But that image on the computer monitor was bright and the best we had obtained with the new equipment, an achievement by itself that relieved us from two years of worry.  Copies of the best raw images and two processed singles are shown in Figure 2. Excessive redness of the raws was a camera setting issue ignored at the time. Compounding our success was the presence of our enthusiastic and  helpful friend Diane Murray, who contributed several digital photographs of us and our equipment; see Figure 3.                                            

    It remained for us to  determine if the satisfactory observation of Mars would carry over to Saturn when it became observable at good altitude during evenings a few months later.  On May 15 we arranged for Prof. Rau to open the observatory in the early evening, which proved to be a winning choice.  The sky had been partly cloudy all day,  the air temperature mild to warm, and the Sun’s heating of the observatory dome  moderate.  At around sunset, when Phil arrived to join Matt, the clouds were fleeing or thinning  and Venus soon appeared in the western sky, so much better placed for viewing from the observatory than expected that we got the telescope up and running quickly and saw the planet’s fat gibbous disc at 100X. That the image was sharp enough at low altitude to show the phase was a good portent. 

As twilight faded toward 9:30 PM,  Matt readied the computer, and Phil wired the Polaris camera.  Saturn became visible at approximately 60 altitude and near culmination, but it was somewhat dimmed by remaining, thin mid-level cloud. We decided to wait for a clearer sky and Phil took a break, including a glimpse at the sky from the ground outside the Science Building.  A  southerly breeze had developed in under ten minutes and had completely cleared most of the sky!  Phil rushed back to the observatory and aimed the telescope at Saturn.  In the 9X50 viewfinder, stars dimmer than ever visible before appeared, and the planet at 100 and 150X was amazingly sharp with two satellites in line with the very narrow rings on each side of the ball.

    With the Polaris camera replacing an eyepiece and the VLC Media Player running, Saturn’s image on the computer  monitor was the best we had seen since 2007.  With the camera’s sensitivity at 2x minimum and exposure ~1/100 sec, the rings were bright and sharp enough to  show both front and back sections, though the planet’s disc was somewhat overexposed, reducing definition of surface detail.  Matt shot several pictures at minimum telescope magnification (f/11) and  the camera zoom off, three being shown in Fig. 4.  Zoom magnification of 1.5x  yielded images just as good so we recorded several more; see Fig. 5 for some of the best. (All shown to here are minimally processed.) A few were sharp enough to enlarge with Photoshop to improve visibility of disc detail; see Fig. 6.  But alas, the breeze that had cleared and stabilized the air over us died as quickly as it had come.  As Phil was adjusting the camera gain upward to display the satellites, and thinking about installing a Barlow lens on the ‘scope, the sky turned murky and Saturn’s image on the monitor dimmed to bare visibility.  Soon the sky was almost totally overcast so we began shutting down our equipment.  But we had done  better than expected in a magical half-hour!

    What our future observing with the B-CU telescope will amount to is very uncertain at the time of preparing this article (July 2010).  We have recovered our 2003-2007 electronic imaging capability and to some extent improved it.  Jupiter and Uranus will be well placed  for evening observing in the autumn.  But whether we will have timely access to the observatory remains to be seen.    

    

    


  
 please click here to return to the index page

this site created using Open Source software