Graze of X32450 - Dec 19, 2004 UT

10.0 star 18s of 54+ moon at 51 deg altitude

Mary and Andy had invited me up for dinner in Bonny Doon. I found this graze conveniently not far away, and I could get it on the drive up. Yes, it's quite the faintest graze I've ever deliberately tried to time, but the weather was excellent and it was no big disruption of my plans. I stopped at a small turnout on Empire Graze, a half mile above "switchback flat" (see here), almost fell into an open manhole(!) and so got into the car and repositioned it so that I wouldn't fall or kick any of my stuff down the hole; then frantically set up, finishing barely in time. Weather was excellent. Seeing was very steady, transparancy excellent.

I aimed for the extreme end of the profile, hoping for significant multiple events. It was a gamble, since this is the same area of the moon grazed a month earlier on my Nov 21 graze, when a north shift almost gave me a miss. I'm still trying to reduce my tape. The path coordinates are here. NAD83 geographic coordinates of my site are below, from GPS.

W. Long. 122deg 06' 54"

N. Lat: 37deg 01' 54"'

elev: 1320 ft.

Datum: NAD 1983

Method: PC164c at prime focus of 10" LX200 a f/10, audio taped of WWV. I carefully stepped through the miniDV tape and recorded the frame number of the events. Then, I calibrated the time:frame count to UT by repeated stopwatch, listening to the nearest minute mark and stopping the stop watch when the next 10sec digit switched, covering the lower digits to avoid anticipation. This calibration is reproducable to 0.15 second. The faint star and made for an additional 0.05 second uncertainty. No correction is made for WWV signal travel time.


begin 2:30:00

D 2:30:50.17 +- 0.2

R 2:30:51.47 +-0.2

D 2:30:51.54 +-0.2

R 2:31:00.67 +-0.2

D 2:31:02.37 +-0.2

R 2:31:40.34 +-0.2

D 2:31:41.00 +-0.2

R 2:31:42.10 +-0.2

end taping 2:33:30