Coyote Lake, 24 Jan. 2006 (Tues)

by Peter Natscher


On Jan 29, 2006, at 12:03 PM, Bob Jardine wrote:

Due to traffic, I didn’t leave home until 7:00, so I got a late start. Kevin S., Peter N., and another gentleman that I didn’t know (Steve?) were already set up.

He was Steve Winston with his 18" GoTo Starmaster, a very nice scope!

No dew at all alonng with no wind--a nice winter evenning. The mag 1 stars weren't scintillating much but seeing was +1 arc-sec overhead and worse towards all horizons. I tried to get a sighting of the Sirius "Pup" but was unsuccessful with my 10" Mak-Cass. Alpha Canis Major was just to upset with the air above to let me see it.

Early on I repeated observations of several asteroids that I had observed at Montebello two nights earlier.

I was watching the bright asteroid Vesta in Gemini a few times during the evening and enjoyed seeing its movement with as little as 15 minutes between sightings.

At 10:30, I did a limiting mag check in the Gemini triangle. Got 10 stars most of the counts and or occasionally 11 (5.7 to 5.9). Peter was getting better than mag 6 higher up in Taurus.

I was able to see as faint as mag. 6.4 stars in Taurus overhead using the triangle star count. The transparency was very good. I also did a threshold star mag. test with my 10" Mak-Cass on a few OC's in Taurus, Auriga, and Gemini and was able to see mag. 14.8-15.0 at 180X despite the soft seeing overhead. That's pretty good for a 10" scope. Saturn was barely showing its Cassini Division as a reference to the variable seeing. My reference is an out of print book named "Visual Astronomy of the Deep Sky", by Roger N. Clark, 1990. It has an appendix with illustrations of nine OC's covering the entire sky along with their star mags. listed so that you can easily find your limiting magnitude.

I enjoyed our short January observing outing, too!


Posted on sf-bay-tac Jan 29, 2006 19:09:33 PT
Converted by report.pm 1.2 Mar 05, 2006 20:32:40 PT