Log, Nov 5, 1999

20+ people. The night promised to be ideal, but alas it didn't come close at all. We were supposed to have clearing by 7 or 8 PM and cooler temperatures. Not so - the temperature actually rose and the clouds came and went with the speed of boxcars on a railway.

A great many people showed up all at once and we are quite sure that many did not sign in tonight. It is very helpful when people sign in and when they contribute to our upkeep. Without these contributions we cannot pay for on going expenses - light, telephone, maintenance, snow plowing, grass cutting, heat - not to mention additional equipment.

Partially because of the weather and partially because of the crowds we spent a great deal of time on Jupiter and Saturn. We also turned to Uranus for a while to let people see a seldom viewed planet. Neptune, Mars and Pluto hid in the clouds whenever we tried for them. Jupiter was it usual grand spectacle. Early on, Io was behind Jupiter and our visitors had a chance to see it pop out of Jupiter's shadow. The other three Galilean moons were visible all night.

As the night went on and Saturn climbed higher, we tried the 5 mm eyepiece. This eyepiece is of a lesser quality than the research grade eyepieces we normally use. At 813 diameters, we expected a washed out low contrast blur. What a surprise - Saturn was wonderful and huge! The rings came close to filling the field of view. Casini's division, the shadow of the planet on the ring, storm belts and the polar darkening were clearly visible. Momentarily we could see gaps between the inner rings. On some perfect night, when Saturn is very high, we will try the 8 mm with a 2x Barlow (effectively a 4 mm) eyepiece. In theory, it should be disappointing, but Saturn at 1000 diameters would be something if it wasn't a complete washout.

After everyone had gone Joe and I tried to split Sirius A and B. Sirius was relatively low, the air was hazy and very unstable and the star twinkled red, white and blue to the naked eye. Both Joe and I had the impression that they could see the very faint B component as a "pimple" on the A component near the bottom. Splitting these two stars is very tricky because of the 10,000 fold difference in their brightness.

We picked out M2, M15 and a number of NGC galaxies for visitors. Our choices were dictated primarily by gaps in the clouds. Later in the evening we did a side by side comparison of M42 (Great Orion Nebula) with and without OXY-III filtering. What a stunning difference. To the unfiltered eye the nebula is rather flat and bland like high overcast. With the filter, we could make out details that made the cloud look more like cumulous nimbus clouds (thunderstorms). The trapezium (Theta-1 Origins) was interesting. With the filter, it was very dim and the relative brightnesses of the 4 components were different than to the unfiltered view.

-Les Coleman

Leslie Coleman
Leslie Coleman
Entry Date:
Nov 5, 1999
Published Under:
Leslie Coleman's Log
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