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Observation Report
Lake Sonoma, Sunday, January 14, 2001

by: Shneor Sherman

I drove to Lake Sonoma Sunday. It's a drive of an hour 50 minutes via highway 37. The site is at at an elevation of around 1,000 feet, and is a parking lot off the road. Car lights are an occasional hazard. I arrived around 4 and set up - while I was setting up, a woman in a pickup apporad=ched me and asked if I would be observing - I told her that I would and invited her to return. She (Chris) returned after dark, and we were joined later by Robert Leyland, a TAC person who's a regular at the site.

There's considerable light pollution at this site (Grey Pine Flat) from the Southand South-East, worse that that at HGO from Auburn and Sacramento. However, most of the Western sky was very dark, the North and East less so. Whiie there are a few distant lights in the valley adjacent, they were barely noticeable. The remarkable thing about this site is the incredible transparency of the air. Just as an example, we viewed M51 at about 19:40 or thereabouts, when it was only 10 or 12 degrees over the horizon. Yet, in my telescope at 158x, the spiral structure was clearlt visible, as was the arm connecting to the adjacent galaxy. The view was not as good as it was at HGO when M51 is at the zenith, but not far. Chris mostly used my 15x70 Bears on a parallelogram mount (though she brought her 10 x 50s - looking to buy a 8"-10" dob), and Robert had an 8" dob (and a pair of Bears). He viewed the double transit on Jupiter. He also showed me a neat little planetary (not in Uranometria, BTW) off the tip of Orion's sword and a bit to the left, that lies in a U-shaped dark cloud.

This site is pretty good despite the light pollution because of the unusual transparency, which Robert says is the usual case at this site. It's probably worth the drive, just 20-30 minutes more for me than HGO. But as it's a longer drive, I think it's preferable on a new moon. One more thing - it was pretty damp, humidity around 88%, though there was a light breese and there was no dewing on exposed eyepieces or any other optics. My eyepiece case, however was wet on the outside and my Sky Atlas 2000 felt pretty damp.

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