Log, Feb 15, 2008

27 people. Francine Jackson and I got to the Observatory quite early last night because the International Space Station (ISS) was due to make a pass over the Observatory just after 6 PM. The Space Shuttle is close by on a servicing and crew exchange mission. We hoped to see them as two separate objects but from FDO they appeared as one object. I had my Astroscan Rich Field Telescope out which can be hand slewed fast enough to track the satellite as well as my large astronomical binoculars. I could not see two objects although the image shows various lumps and irregularities which I assume were the Shuttle as well as various solar panels and what have you. In my usual bombastic style, I predicted that we'd see the ISS all the way to the horizon. A visitor said he thought the ISS would actually go into the shadow of the Earth. I thought this wasn't likely so soon after sunset. Our visitor was right! By the way, Ernie Evans reported that he managed to see the ISS and Shuttle with an intervening space. He was far enough west at the time that this was perhaps the case. Either that or he looked at them while I was looking at them with my eye.

Our founder, Bill Penhallow made an appearance last night to my surprise. Welcome, Bill! He got a chance to see the Dog Star (Sirius A) through our brand new apodizing filter. This weird filter is designed to extract light from bright objects while preserving light from dim objects (errr - sort of). It was able to extract enough light from the Dog Star that I got my first unambiguous view of the Pup (Sirius B), the dim White Dwarf companion star of mighty Sirius. Several of us could see the Pup but it took luck to get a stable enough moment to allow the Pup to shine through our turbulent air.

We had previously tried an apodizing mask Ernie had created for his 11" scope using a jury rig system. It sort of worked, but the mask was not easy to center, and the images it produces caused the spectral patterns to broaden. As I promised, I created an apodizing mask for the 16". I wanted it to have several features - light weight, strength and rigidity, the correct 16" size and ease of installation. I got most of what I wanted but it wasn't quite as light as I had hoped. I'll need to adjust this with some counterweights the next time we use it. When I built it, I sent a note to Ernie and Francine saying that I either had a workable gadget or a circular window screen with a hole in the center large enough for a pigeon to fly through. Sorry pigeons, the mask is now permanently a tool at FDO. The thing worked remarkably well. I definitely saw Sirius B (the Pup). The spectral patterns were much sharper than the jury rigged system. We also tried it on Rigel and the results were spectacular. We split Rigel easily with a large clear band between the two stars. Easily the best split of Rigel I can remember.

Various groups of people filtered in at various times so we did a lot of switching between Saturn and M42. Mars and the Moon were close together but nearly vertical so they could not be viewed by the big scope. However, I made a lot of kids happy when I took the Astroscan out in the yard. They could look at the Moon through it or Mars or anything else they wanted to see.

The weather was perhaps the only negative other than a bright Moon that made faint fuzzies out of the question. It suddenly got very chilly (lower 20s?) and a heavy wind came up. This combination (rapid temperature change and wind) made "seeing" relatively unstable. For example, I kept getting glimpses of the Cassini Division on Saturn's Ring System only to have it fade away. We finally had to shut the door because the wind was tearing things from the wall. Then to make matters worse, clouds started to roll in at 10 to 11 PM.

-Les Coleman

Leslie Coleman
Leslie Coleman
Entry Date:
Feb 15, 2008
Published Under:
Leslie Coleman's Log
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