Log, Jan 23, 2004

11 people - Joe Hartley reporting. The night started for me on my drive to Charlestown as I saw the moon, a day past new, sinking into the west with Venus shining brilliantly above it, bright portents of the evening to come.

I arrived at the dome at 6:45 (late again!) and was startled to see what appeared to be a lens about 4" in diameter on the floor. Upon closer inspection, it was a piece of ice that had formed from a leak in the dome. Perfectly circular and transparent, it was a reminder of the harsh conditions we expect the telescope to function under.

The scope was fine, though. Starting the night with a quick 2-star alignment gave us perfect pointing all night long.

We had 4 small family groups visit us in the first hour, and we had an enjoyable time in the eastern sky with Saturn, the Orion Nebula and the Eskimo Nebula. On this last object, we had a surprised Cub Scout look in the eyepiece and exclaim "It blinked!" This was not his imagination, but his awareness of how important peripheral vision is to observing.

The center of our retina is packed with sensors that detect color well, and are not as sensitive to faint light. Around those sensors, in our peripheral vision, are the sensors that are much more sensitive to faint light. When we look directly at a nebula such as the Eskimo, we don't see the faint halo around the center star nearly as well as the center star, but it's very prominent when looking just off to the side. The overall result is an object that "blinks" when you look at it.

By just after 8, Ernie and I had the scope all to ourselves on a very clear and cold night. Ernie had come with a list of potential targets, and I am always happy to try and see what can be seen.

The first was NGC 2169, an open cluster in Orion that has been mentioned in Sky & Telescope as the "37" cluster. This cluster has 2 distinct groups of stars that line up in rough geometrical forms that suggest a number of different names. In our Schmidt-Cassegrain scope, our reflected image is different than in Newtonian or refracting scopes. Our view is reversed from the person who gave this cluster its nickname, so the "3" looked to my eyes much more like the Greek letter sigma, or an hourglass, or a martini glass!

Next up was NGC 2403, a wonderful face-on spiral galaxy in Camelopardalis. Some structure was evident, making this a nice view. We then went to NGC 1023, another galaxy, this time in Perseus. This was smaller in the eyepiece than 2403, showing mostly core, but was still very nice. From there we went to NGC 891 in Andromeda. We've seen this before in the 16" and we were a little surprised at its faintness tonight. It was still very nice, stretching across the eyepiece with its dark lane visible.

Staying to the north, we saw NGC 457, an open cluster in Cassiopeia. This is sometimes called the Owl cluster after the 2 bright stars at one end of the cluster, resembling a pair of owl's eyes. Ernie said that it's also called the walking man or the stick man cluster, but someone with a better imagination than us seems to have come up with that name.

We then tried for NGC 7635, the bubble nebula, but we were not able to discern much nebulosity at all. Perhaps another night. We then went to M52, another nice Cassiopeia cluster.

We then went back to the south to view NGC 2360, an open cluster in Canis Major. This was a nice view, as was NGC 2359, a nebula known as "Thor's Helmet". The swooping shape of this reminds some of the horns on a Viking helmet.

We made an attempt at viewing the Horsehead Nebula, but there was not much contrast, and neither of us were familiar enough with its neighbors to locate it. We finished off with an attempt to split Sirius, but even with all manner of filters and magnification, we were thwarted by the extreme brilliance of Sirius A, and the fact that the scope's optics are in need of collimation, a task that takes 2 staff members, a clear steady night and patience!

It was 11 PM and 13 degrees as we called it a night and packed up for home.

Leslie Coleman
Leslie Coleman
Entry Date:
Jan 23, 2004
Published Under:
Leslie Coleman's Log
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