Occultation of Aldebaran
from the
Weaver Student Observatory
Click on image for a wider view.
Click on image for a wider view.
A January meeting coincided with a lunar occultation of Aldebaran and, what¼s more, with a clear sky. Arthur Babcock, Robin Casady, Kim Cohan, Paul and Ileene Franks, Bob Trubell, and Zena Zeres observed the eclipse and reappearance of Aldebaran from the Weaver Student Observatory at MIRA¼s Marina site. We recorded the event on videotape using a CCD camera mounted to the 4" refractor.
Here is the tale of the occultation by Arthur Babcock
It got clearer and clearer as the night wore on--at occultation time, it was almost completely clear. We got the video on the 4" refractor going, running it to the TV/VCR combination.
Unfortunately, the crappy shortwave radio I bought to provide time signals wouldn't receive WWV inside the observatory, so I was reduced to putting visual time signals on the tape by looking at my watch (synchronized to WWV) and flipping on the crosshairs generator at one-minute intervals.
Kim Cohan showed up and cobbled up a long-range audio cable so the blasted radio could stay outside and still connect to the audio input on the VCR. It was still marginal, but we got two clear signals, one at 11:41:00 and another at 11:42:00. This was AFTER Aldebaran was covered, but you can work backwards as easily as forwards, so I calculate that Aldebaran was covered by the Moon at 11:37:38, +/- .5 second. I ought to be able to get closer than that if I figure out a way to count frames accurately. BTW, the star took 3 frames (@ 1/30 second each) to disappear.
Aldebaran was drifting a little as we tracked it approaching the occultation, so for the reappearance, we guessed what part of the Moon to point at, based on a drawing in Sky and Telescope. Sure enough, the star turned up there, almost exactly one hour after disappearing. I haven't calculated the reappearance time yet.
Christopher Allan was kind enough to digitize the image from the video tape at New Dawn Studios. Robin Casady did a little post processing to prepare the image for the web.