Graze of X057289 - Dec 20, 2004 UT

10.0 star 17.6s of 65+ Moon at 52deg altitude

My success with a 10.0 magnitude star on the previous night's 54% moon emboldened me to try this tougher one; 10.0 on a 66% moon from the damp, bad seeing environs of Cabrillo Observatory. I'd hoped Shahram would show up and keep me company and we could accomplish some Comet Machholz photography and other projects even if the graze was too tough. The marine layer returned; low, but definite. Very damp conditions and poor seeing at the observatory. I tried in the 10" at f/10 first with an eyepiece and had no luck at all finding the star an hour before the graze. It looked hopeless on this scope, so I went into the dome and put the PC164c on the 12" with f/6.3 focal reducer. I was able to see the star briefly before the graze as I tried to get good focus, but then lost it and missed the first D. Difficult to say when I should have been able to get the next events. The camcorder was running, but the star was SO difficult to see and the seeing did vary.... However, I did get the final "R". I'd hoped to get a peak which showed on the profile at this 1.72mi S location, but it looks like there was a small south shift and so only the final "R" and a brief D-R a few seconds later were recorded.

Graze profile and graze path

Location: Cabrillo College Observatory

Telescope: 12" f/10 LX200 with f/6.3 focal reducer, permanent equatorial mount.

W.Long = 121 55' 27.3"

N. Lat = 36 59' 34.1"

Elev = 190 ft.


R: 04:15:05.95 +-0.25

D: 04:15:06.35 +-0.25

R: 04:16:07.95 +-0.2