On the night of Saturday, April 10, 1999, a bunch of us
We set up the Meade 10" telescope with f/6.3 focal reducer, and attached the intensified video camera to it. Tracy Davis brought his WWV receiver, which picked up time signals from Fort Collins clearly. I brought an audio tape recorder, and set it up so that it recorded the time signals and our voices in the 10" dome. Tracy aligned the finder on the Meade 10", reset the telescope coordinates on a bright star or two, and then moved to the field of Ophelia. It took us only about five minutes to find and verify the field. We were all set up and ready to tape the event 90 minutes before it started.
The short version of the story is: we didn't see any dimming of the star within 20 minutes either way of the predicted time.
The long version of the story: we started videotaping at 2:46 UT 11 Apr 1999. At 2:47 and 2:48 UT, Tracy held the lens cover in front of the telescope for 10 seconds (from top of the minute to 10 seconds past the minute). We thought this would put a good time signal on the videotape itself. At 2:49 UT, he held the lens cap in front of the telescope for 15 seconds (from 2:49:00 to 2:49:15).
From 2:49:15 UT until 3:30:00 UT, there were at least three pairs of eyes watching the TV screen at all times. No dimming of TYC 1878 00551 was seen. I watched the videotape again the next morning, and again did not see any evidence for an occultation. Rats!
On the TV screen in real-time, we thought we could see stars down to around 13'th magnitude. Here's a video capture of a single frame, and a median of three frames. North is at the top, and east to the left. Click on an image to see a full-size GIF image.
Here's a chart showing the magnitudes of stars in the field (most come from the Hubble Guide Star Catalog, and so are only good to half a magnitude or so):
Finally, here's a side-by-side comparison of a three-frame median (taken well before the expected time of event) and a five-frame median (taken at about the expected time of the event):
I reported our null result to IOTA -- I hope that it helps someone to improve the orbit of Ophelia.
I also hope that we actually do see an occultation someday!
In order to boost our spirits, we decided to do a little extra observing while we were there.
Jim wanted to see how well the camera could pick up faint, extended sources. He moved to the galaxy NGC 2903, a spiral in Leo with integrated magnitude 8.9. Here's what the galaxy looks like on the Palomar Sky Survey plates:
We were able to see the nucleus of the galaxy clearly on the TV screen that night, and we could make out very faintly an elongation in the north-south direction. Images captured from the videotape don't show as much detail as we could see in real-time. Below are a single captured frame (on left), and a median combination of three captured frames (on right):
The bright star at upper left is PPM 99669, magnitude 9.9. The three faint stars below the galaxy have magnitudes (from left to right) 11.4, 11.4, 12.6.
Since Mars was rising in the East after we gave up on the occultation, we decided to take a look at it. We switched cameras, replacing the intensified video camera with the Astrovid camera. We also removed the focal reducer from the Meade telescope, in order to project as large an image of Mars as possible onto the camera.
We were mildly pleased with the images shown on the TV screen in real-time. We could a very few features: a dark splotch on the left-hand side of the disk. Perhaps it was Syrtis Major? The captured video images are again worse than the real-time view. Using Photoshop, I tried enhancing the images with unsharp masking:
And here are a few more processed frames: these may look better if you download then to your local computer (by clicking on an image), and then examine them with some graphics program.
Note that the images of Mars are about 15 pixels in diameter, which really isn't enough to show good detail. Mars was 15 arcsec in diameter at the time of the pictures. It would be better to use the 16" telescope, which has a focal length about 2.4 times longer than the Meade 10", to take future pictures of the Red Planet.
We then looked at Mars visually through the 16" telescope. We tried without any filter, and with red and yellow filters. I think that the filters helped to show the surface features a bit. We could see one of the polar caps clearly, on the left limb, with a dark "collar" separating it from the main part of the disk. We could also see a dark splotch on the disk itself, slightly below center and to the left. There were hints of more detail, but only once or twice per ten-second interval at the eyepiece: we had to wait for rare moments when the air was momentarily still.