Log, Jul 4, 2003

15 people. Independence Day was hazy, hot and humid and in spite of a favorable forecast for seeing by the Clear Sky Clock, viewing was miserable. The Sun set a lovely shade of mauve - a color one seldom associates with a G2-III star. People remarked that the Moon was a lovely orange brown shades - but the astronomers amongst us cringed at the thought of how much haze was required to produce these weird tints. In every direction, fireworks illuminated the sky with various shades of blue, white, red, gold and violet. We could see the Charlestown display all to well - it was less than a half mile away. Point Judith, Kingston, Block Island, Misquamicut and downtown Westerly twinkled, flared and boomed away. We even had someone fire a rocket that went over the Dome about 7:30.

Besides enough moisture to drench a forest fire into submission, the air was full of another seasonal problem. Mosquitoes - and I sure ticks, chiggers and deer flies.

The telescope was acting up again. For some reason, I can't seem to get and hold a decent alignment. I'm going to have to prevail on the technically more adroit members of FDO to come over some non-Friday night to help me find out what is wrong - either with my setup or the scope. We'll schedule such a night when I return from my sabbatical.

We looked at the Moon, several double stars and M57. Deep space objects overhead were viewable but even bright objects like M4 were totally washed out. We could see it, but it looked like a gas cloud rather than a brilliant globular cluster.

At 10:20:31, the Sun (by then well below the horizon) flashed off the solar cell arrays of Iridium 22 causing a 3 second long -6th magnitude flash just above and to the left (facing west) at the Observatory. This particular flash was more than five times brighter than Venus at its brightest - out shown only by the Sun and the Moon this Independence Day. The center of the flash passed only 10.9 miles east of us along the Charlestown/Kingston border. It is rather special to be so favorably placed. We missed the absolute best view of this flash by only a tenth of a magnitude. A strata of clouds made the viewing doubtful at all, and haze hid any low light level before and after trails. As I said to the people watching, we might be the only people who happen to see this flash. Roger and Ernie were using Roger's 4 inch refractor while I had the crowd along the walkway. To the northwest, Charlestown was concluding their fireworks display. Sure enough, exactly on time the satellite reflected the Sun. However two guys managed to miss it - who you might ask? Why of course the two guys with the most years of experience who should have known better - Ernie and me.

One of the advantages of the ever improving software for guiding telescopes and for "planetarium displays" is that they now allow us to track satellite. Orbital elements for more than 10,000 objects are available. I've downloaded the Iridium, ISS, GSP and a number of geo-synchronous satellite elements. I ran the software after I had seen in Heavens-Above.com that a flash could be expected. For example, at the instant of the flash, Iridium 22 was 1109 miles from the Dome somewhere over the Midwest. I also saw that another 7 or eight Iridium satellites would pass above, over and below the Moon last night although only Iridium 22 at 10:20:31 would flash brightly. Most of the rest stayed at magnitudes so low that binoculars would be required. It was very helpful to pre-plot the track so that people could look exactly in the right place.

I will be away for the next two Fridays. In my absence the Observatory will be closed. See you again on July 25th weather permitting.

-Les Coleman

Leslie Coleman
Leslie Coleman
Entry Date:
Jul 4, 2003
Published Under:
Leslie Coleman's Log
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