Jupiter. With a 9.8" Newtonian reflector at ~f/4.6. Edmund Scientific 15mm RKE eyepiece, combined with a University Optics Klee barlow, rendered a magnification of 213x, University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x. 0815 Sep 15 UT, System I longitude 289, system II longitude 276. Good seeing tonight resulted in a good look at the separation between the SEBs and SEBn; it is not clear to me that I have observed this as well this apparition and I am contemplating the possibility that September 10th's sketch, which shows the breakup of the disturbance into a row of ovals, is partly illusory. Note the small elongated spot just P of the central meridian in the southern part of the NEB. This spot was remarkably bright, and was almost remeniscent of a specular reflection. The dark dot south of the SEBs on the F side of the planet is the shadow of Ganymede.
Jupiter. With a 9.8" Newtonian reflector at ~f/4.6. Edmund Scientific 15mm RKE eyepiece, combined with a University Optics Klee barlow, rendered a magnification of 213x. Sep 14 1052 UT, System I longitude 228, System II longitude 221. Night of poor seeing. Only the grossest features were distinguishable, including persistent lumpiness in the NEB and some of the white ovals in the SEB.
Jupiter. With a 9.8" Newtonian reflector at ~f/4.6. Edmund Scientific 15mm RKE eyepiece, combined with a University Optics Klee barlow, rendered a magnification of 213x. Sep 11 1012 UT, System I longitude 88, System II longitude 105. The GRSH is rotating off the globe in this view and the SEB areas following it are well observed. Seeing was fast, and belts were well differentiated, but difficulties in detecting faint contrasting belt details were experienced.
Jupiter. With a 9.8" Newtonian reflector at ~f/4.6. Edmund Scientific 15mm RKE eyepiece, combined with a University Optics Klee barlow, rendered a magnification of 213x. Sep 10 0900 UT, System I longitude246, System II longitude 271. Poor seeing required me to pick and choose which parts of the globe I wanted a good look at. I ended up with a good look at larger scale spots in the SEB, which make up the SEB Disturbance.
Finally, another clear night during the monsoon season. Tonight was the first dewy night I experienced, and the dew situation was very bad. The seeing was pretty good, but I only managed a mediocre sketch due to all the water.
Jupiter. With a 9.8" Newtonian reflector at ~f/4.6. University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x. August 24 0940 UT, System I longitude 104, system II 258. The long, curved dark feature arcing P of the GRSH was about as dark as the NEB. The GRSH did include an obvious bump, but no apparent GRS was visible.
We finally had a break in the monsoons the morning of August 4, 1998, and I took advantage of it for observations of Jupiter and Saturn. The seeing was fairly poor, featuring intermittent periods of image jumpiness, and overall rating a 4/10. Fortunately, there were protracted periods of steadiness that I was able to exploit.
Jupiter. With a 9.8" Newtonian reflector at ~f/4.6. University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x. 10:20 UT Aug 04. System I longitude 208, System II longitude 154.5. This sketch adopts new techniques as advised by Rik Hill on the Shallow Sky mailing list. P is left, N is down. The most curious feature of this observation is the large triangular dark area extending from the north pole well to the south. This feature was rather apparent to the eye and appeared blue in color in an unfiltered estimate.
Saturn. With a 9.8" Newtonian reflector at ~f/4.6. University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x. P is left and N is down. ~11:00 UT Aug 4. Also using the new sketching technique. ALERT: The equatorial zone is much brighter than at my last careful observation, made on 11 July. Also, the equatorial belt has dramatically reduced intensity or disappeared.
We had a morning of sub-arcsecond seeing between about 0900 and 1300 July 10 UT, at my backyard observing site in Sierra Vista, Arizona. The naked-eye limiting magnitude at the zenith was approximately 2.3, and the sky was quite hazy. Combined with the full moon, even M31 was barely visible in a 10" f/4.5 telescope. This rendered the night completely useless for any sort of deep sky observing.
However, there were compensations. The seeing was extremely steady. On the old one to five scale, it was a true five. On the Pickering 1-10 scale, it was a ten. This can confuse, so I will explain clearly what I mean by these numbers. The disc of a star was always sharply defined, and the diffraction rings stationary, at an altitude of 30 degrees! When observing the moon, no shimmering or blurring of the limb or of surface markings was apparent. No shimmering or blurring was apparent on any planet. Out of focus stars were evenly illuminated across the entire 'donut', with no waves or shimmers passing through the air mass.
Seeing of this caliber I have probably never experienced before. My logbook indicates only two nights (of over a thousand that I observed) in which I rated the seeing as a "5" on the old scale. Those nights were probably not as quite as good as this night. When I discovered the seeing was excellent, I had just set up my telescope at about 0900 UT in preparation for making planned Jupiter observations 2 hours later. Jupiter was rock steady at that time (at a local altitude of 31 degrees), and Saturn, which was only at altitude 12 degrees, was showing Cassini's Division across the entire face of the rings and both ansae, and was generally speaking as good a view of the planet as I normally get.
I took the opportunity to star test the telescope. The scope is a 10" Meade Starfinder Equatorial, a sort of half-hearted commercial offering that has a lot of shortcomings. The optics are not one of them. The star test revealed a slight turned-down edge. I quickly cut a mask to stop the mirror to 9.8 inches, and the TDE disappeared in the star test. For all intents and purposes, the star test after the mask looked perfect - no doubt it was not perfect, but I could not tell the difference.
I then made an observation of Uranus, executing a sketch. "P" indicates the preceding (in drift) side of the planet, and "N" indicates celestial north in the sketch.
Uranus, 0944 July 10 UT. With a 9.8" Newtonian reflector at ~f/4.6. University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x. Uranus is very difficult to focus, and this accounts for many observers' failure to see broad features on the globe. The dimming of the edges of this planet is rather dramatic. A nearby star was focused precisely, and the telescope slewed to the planet. Limb darkening is depicted, as are three large dark areas seen with extreme difficulty, and one brighter feature seen off the center of the planet rather easily. This is only the second time that I recall seeing any detail on this planet, in some 20 years of observing. A very faint star was about three planet diameters to the north and slightly preceding.
After spending approximately a half hour on Uranus, I moved to Jupiter.
Jupiter, 10:05 to 10:18 July 10 UT. With a 9.8" Newtonian reflector at ~f/4.6. University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x. This sketch is entirely inadequate; far more detail was observed than could possibly be recorded. During this sketch, Europa was in transit, clearly seen as a bright disk passing over the face of the planet. It is not depicted on the sketch. P is left and N is at bottom. The most obvious features of the globe were the lumpiness of all belts, the bright area in the center of the disk bordered by two festoons, and the seemingly endless supply of light yellow spots in the STB, some of which are depicted here with dark contrasting features between them. Two large bright features in the NNTB (?) were also fairly conspicuous. Most interesting perhaps is the change in weighting of the rift in the STB from N to S as the following edge is approached. A broken equatorial belt was seen. In the south polar region, the P side was considerably darker than the F. On the F side, however, the dark region seemed to reach north and overrun other features. The drawing is, unfortunately, rather poorly executed, due to the great haste necessary and the overwhelming number of features.
At the magnifications employed, the Jovian satellites were clearly disks. Even Io, at about 1 second in diameter, was showing some hints of detail. This size is just at the limits of the resolution of a 10" telescope. After only a cursory look of about five minutes or so, I drew what I thought I could see:
Io, 10:31 July 10 UT. With a 9.8" Newtonian reflector at ~f/4.6. University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x. No part of this sketch should be considered accurate. P is left, N is down. The only thing I am willing to commit to is that the F edge was definitely darker than the rest of the globe. The other two features were suspected at times, but never clearly seen.
Venus was also inspected but proved to offer nothing of interest. The observing session was closed, and this web page written up before fixative was even sprayed on the sketches.
Jupiter, July 11 10:25-10:44 UT. With a 9.8" Newtonian reflector at ~f/4.6. University Optics 9mm Abbe Orthoscopic, combined with a University Optics Klee barlow, rendered a magnification of 354x, and with other magnifications. P is left and N is down. This sketch is a much better rendering of what was seen than the one done the previous day (reproduced above). The seeing was fairly stable, with long periods of steadiness, but was not as good as the previous morning's. This sketch was never 'finished', but shows a profusion of white ovals and other features all over the globe.
Jeff Medkeff's home page.
Jeff's astronomy pages.
Copyright © Jeff Medkeff, 2002, All Rights Reserved.