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Log, Apr 21, 2006

16 people. Earlier in the afternoon, I attended the Frosty Drew Memorial Fund Board meeting for April. The sky was clear and the sun was bright. I had high hopes for the evening. [Then again, several of my buddies have accused me of setting up in a pouring rain. This is a foul canard - I rarely set up in anything much worse a steady drizzle.] In any case, we didn't have rain but we did have a fairly thick high overcast. Yes you could see things through it, but anything dimmer than the third magnitude disappeared. Just before closing Ernie and I saw a really unusual meteorological display. Towards the northeast (Providence/Warwick/Cranston), a semicircular cloud with rays was highlighted against the sky. It looks rather like Lady Liberty's head dress as seen from the entrance to the Statue of Liberty. Ernie said it looked like an aurora, and indeed it did, but it was merely a cloud and contrails from planes leaving T. F. Green Airport.

We had a couple of families as well as several adult groupings tonight. The kids were remarkably well informed which always pleases me no end. Now we never mention the kids by name in this site to avoid some very nasty internet lurkers but you will not find a bunch of nicer kids anywhere. We discussed a whole variety of subjects including why Mercury has small craters while the other rocky planets and moons have much larger craters. [Mercury lost most of it rocky mantle near the end of the barrage of asteroids that accompanied the formation of the solar system.] We compared the images of the major planets to each other, noting things like storms on Jupiter and Neptune, the Rings of Saturn and the surfaces of Mars (visual) and Venus (via radar). We did the standard sky identification, saying hello to the first of the summer constellations and bidding farewell to the last of winter's constellations. In fact tonight may be the last time we see M42/M43[the Great Nebula in Orion] until next Hunter was already setting as we arrived.

We started with Mars (and went on to M42). Mars is quite small - about 5 arc minutes across for a disk. Saturn hid behind the dome's shutter when we started. We actually first saw Saturn through the big lenses of the 16" Meade before it could be seen in the spotting telescope mounted on top of the main scope's optical train. I tried to see disks for Titan (Saturn) and later for Ganymede (Jupiter) since both are big enough but the seeing prevented it. In fact, Jupiter was largely a washout. Jupiter was so bright, that the thin cloud layer here acted like a bright moonlit night.

While we were outside looking at the constellations, Ernie spotted what has to be an Iridium satellite. We watched it brighten to about the minus fourth magnitude (rivaling Venus) and then dim down to invisibility. I told the story of the ill fated attempt to make a cell phone system which was tied to satellites rather than cell towers. The kids found the idea of cell phone's almost as heavy as bricks a bit ridiculous. Come to think of it, a cell phone with such a heavy battery pack IS ridiculous. I rarely want to call someone on his cell phone while he is crossing Antarctica, and this is about the only thing the Iridiums can do that cannot be done just as well by a compact sized phone.

Ernie had several "want to sees" tonight but we really only got to see a few. One rather spectacular galaxy was NGC4565 which is an edge on galaxy somewhat like the Sombrero (M104). We compared it to M104 which is brighter but both are interesting. We also looked at Schwassmann-Wachmann using some coordinates that Ernie had interpolated from a map he had. Tonight we could see the head, and a fan shaped tail with two main parts, a brighter lower side that shot basically backwards from the comet and a slightly curved upper portion. These two tail parts are caused by differing types of ejecta from the comet. Straight parts tend to be particulate and curved parts tend to be gaseous and swept back by the solar wind. We wanted to try for the comet earlier but clouds made this impractical. It was interesting to note that between when Ernie had interpolated the position (basically for early evening) and when we actually saw the comet (after 11 PM) the coordinates had changed by several arc mi right ascension and declination.

-Les Coleman

Leslie Coleman
Leslie Coleman
Entry Date:
Apr 21, 2006
Published Under:
Leslie Coleman's Log
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