Thanks all.

Finding it wasn't hard once I had good orbital elements but seeing it was. It was predicted at 17.8 magnitude which is easy for a slow moving asteroid in the main belt but not one speeding by at less than a half million miles away. It was on any one pixel for less than a second when tracking at sideral rate so didn't show. It was only after I programmed in the offsets in both axes that it showed up. Centering it turned off the asteroid tracking and turning that back on took time, moving it well off center by the time I could do so. I finally estimated where it would be one minute later, centered that, started the offset tracking rates and started recording. It worked.

Now if we get another one I'll know what to do. Also my brain doesn't function at anywhere near full capacity at 5 a.m. which didn't help. I did forget to turn on PEC so there's some wobble to the star tracks. Fortunately, even without PEC activated the tracking error is not much greater than my seeing.

Rick