Observer: Richard Nolthenius (831) 479-6506, rinolthe at cabrillo.edu
Asteroid, Star: (552) Sigelinde, TYC 0237-00673-1
Telescope: 10" Meade LX200 f/10, Alt-Az, 22mm Nagler
Location:Cabrillo Observatory, W.Long= 121 55 27.2, N. Lat 36 59 34.0, elev 190ft, NAD83 coordinates from USGS map at topozone.com
Method: Voice/WWV/tape recorder
Sky: clear, excellent seeing, star+asteroid merge visibility: about 1magnitude above mag limit.
Timings: Mar 11, 2007 UT
D: 10:04:23.26 +-0.29 RT=0.63
R: 06:13:02.23+- 0.14sec, RT=0.37sec
Comments: Clear skies, some cirrus but not near star. 50% moon behind Hort hill. Very good seeing. Tried to drag out 12" Dob on my own, but too heavy. So 10" Meade LX200 with lame'd drive was the best remaining choice. I'd left Chris Angelos at Bonny Doon to try it from there. But he had inexperience problems despite the good conditions and early locating of the star. Not sure exactly what the failure mode was, but his track was -19 and not much different than mine (-27) anyway. Used Voice/WWV. Star was faint but steady. Visible best with averted vision but didn't have to be too picky about getting the averted vision location in the sweet spot. However, it did cause me to get a late "D" as I was worried it might have slipped to the worst spot of my averted vision when in fact it had actually "D"'d. The R was solid and in fact faded in during a little over 0.1 second.
Here's the Excel report, and the skyplane plot of all observations.