Log, May 19, 2006

3 people. Following an afternoon session of the Frosty Drew directors at the Nature Center, I was sure that we would open, but by the time I got home some fifteen miles to the west I was in a thundershower. The upshot was that at various times I posted a "doubtful" question mark logo, and then went back to the open observatory logo. I arrived just before what was sunset (if I could have seen the Sun) to a bank of clouds. Nick Teta was waiting there and made remarks about being unsure if we were opening or not. I simply waved my hand at the various clouds and muttered under my breath. Later in the evening when Ernie Evans showed up he made his usual remarks about "It must be Friday at FDO, its getting cloudy". Worse yet, the sky opened here and there, and then shut down almost completely only to open again. I think it would have been a fairly good night if it wasn't for the wind causing twinkling of stars. The air was certainly clear enough. Actually, just before quite clear and stable but I had to drive to New York in the morning so we didn't stay to the bitter end.

Since we had no one who wanted to see the usual cast of characters, we figured that we'd look for faint objects. Oops, high clouds - so back to the usual cast of characters. Nick and I played games trying to see how soon after sunset, we could spot Saturn against the still blue sky. There is a trick to looking for planets (and actually one or two stars as well) in the twilight sky. You have to focus at infinity. If your eyes focus nearer, then the faint contrast causes the planet to disappear. Also "saccades" (the automatic tendency of the eye to wander when looking at a nearly featureless background) makes it difficult to avoid drifting away from where you expect to see the planet. Saccades can be rather dramatic. Go outside and look at a clear area of the sky - say 45 degrees up from due south. Try to stay there and you will find you eye drifts a long way (20-30 degrees in some direction or other) unless you are very precise.

When it got clear enough we tried for some more interesting objects. We split several very spectacular double stars. Even small scopes will let you split some like Castor. Then we tried to see how many galaxies we could crowd into a single eyepiece view. This means dropping the magnification to the lowest possible power (about 55 times on our telescope) and widest angle. We don't use that giant eyepiece very often for anything except the Moon, but that’s a pity because it really provides glorious wide angle views. I really liked the M105 group which shows three relatively bright galaxies (M105, NGC3389 and NGC3384) at the same time. We thought of trying for the Abell cluster of galaxies (6 galaxies in our eyepiece) but guess what? Clouds.

Ernie and I tried to decide if M104's "dark lane" was truly a dark lane or simply a dark fringe tonight. Ernie said fringe and I said that I could glimpse a bit of starlight below the band so that it was a dark lane. It is one of those fruitless debates which old timers mutter at each other. The truth of the matter is that everyone's eyes are unique and what one person sees as a faint contrast another cannot see. We tried to examine M104 in a wide variety of eyepieces. It didn't settle the debate.

We saw Iapetus last night. This distant moon of Saturn is often overlooked because it is so far from the planet. It has a bright and a dark side making it hard to see at some angles. In any case, it was quite clear last night. We also saw Vesta which I haven't seen in more than a year. Vesta is one of the brightest asteroids. In the scope, the only way we could tell it was Vesta was than it was a modestly bright "star" where no star existed.

-Les Coleman

Leslie Coleman
Leslie Coleman
Entry Date:
May 19, 2006
Published Under:
Leslie Coleman's Log
Subscribe to Leslie Coleman's Log RSS Feed