In the first half of 2007 we had our last chance for several years to observe Saturn with its rings tilted enough to exhibit major details. Furthermore, the next favorable period, with the north face visible, will occur when the planet is low in the Zodiac, an evening-sky object during our poor weather months, and at or near orbital aphelion.
At opposition to the Sun on February 10, Saturn wasn't high in the early to mid-evening sky until several weeks later, and we didn't get around to observing it with the Bethune Cookman C-14 until April. On the 13th, with broken low clouds drifting rapidly across a slightly hazy sky, we saw the planet's image unexpectedly sharp and bright at medium magnification near 9 P.M. The Polaris camera was handy and Matt had reinstalled an old but functional PowerMac computer near the telescope, so we were set to do videography.
In a few minutes the camera was in the 'scope's eyepiece holder and its VHS output connected to the computer. After some camera adjustments the computer's video player produced remarkably good images of Saturn on the monitor at lowest or 2X camera response. (Sky transparency was somewhat variable.) Amazingly, the 'scope's drive performed better than during any of our previous planetary videography sessions dating back to early 2003. No periodic image wobble, no sudden drift! The image quality was almost as good with the camera's digital zoom active, yielding up to 300 inches focal length, as without it (150 inches).
Numerous still frames were captured with the computer during almost two hours, and quick looks revealed images as good as or better than we had obtained before by stacking 4 or 8 raws! A selection of April 13 images follows this text.
We returned to the B-CU observatory in the evening of June 9, observing Venus as a thick crescent, Saturn, and Jupiter, but only visually as the sky was hazy and the seeing mediocre due to lingering heat from a 90 degree day. A late view of a double star revealed elongated individual images, which had to be due to misalignment of the elbow mirror in the telescope's tailpiece or of the secondary mirror, behind the corrector plate. We quickly eliminated the first possibility and, using defocused Antares as a test source, adjusted the secondary's alignment screws to restore a circular image.
On June 15 we opened the observatory again. The air was cooler and the sky clearer than on the 9th, with only a few fast-moving low clouds. This time we had several visitors including our friend and occasional collaborator, Diane Murray. Once again we viewed a crescent Venus and Saturn early, and Jupiter about two hours later, when it was relatively high in northern Scorpius and showed good detail. In July Matt ended his employment at B-CU, moving to a new job at a local high school. Whether we will do any more observing with the C-14 is uncertain at the time of writing.
As Matt was changing jobs we established an account to use the Bradford Robotic Telescope observatory on Tenerife in the Canary Islands, a territory of Spain located off the northwest coast of Africa. Operated by a team for the University of Bradford in England and funded by private donations, the observatory has a C-14 telescope and two piggybacked, fast telephoto cameras with electronic imagers. Its site is atop a mountain nearly 8,000 feet above sea level and about one degree of latitude south of Daytona Beach. Much more information about it can be found at www.telescope.org.
Considering that the BRT has 20,000 users, we were pleasantly surprised that five requests for observations with the C-14 were granted after an average of only three days each. On the other hand, the telescope and/or its Galaxy CCD camera at an f/7.4 focus performed below their best levels. In the summer of 2006 the instrument had broken down, and after being reactivated months later was still in a beta-test condition when our use began. Processed single images of three objects--the globular cluster M80, Neptune with Triton, and the galaxy NGC 7331--are shown below. All are affected by telescope drive errors and the first two by mediocre focus. The galaxy pictures, compared with a color picture in the November 2007 Sky and Telescope, p. 74, implies spatial detail, perhaps a good deal, was lost due to the poor tracking.
We intend to request more BRT observations in hope that the focusing and tracking are significantly improved.
M80 imaged by the Bradford telescope on August 7, 2007 at 22:31 UT.
The 16-second raw, RGB exposure has been enhanced using the iMac PREVIEW utility.
The original is Copyright, Bradford Robotic Telescope.
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