Minor planet 16 Psyche
This photo is made from a sequence taken at 4 minute intervals for just over an hour. It was apparent from this chart that Psyche was moving at about 0.25° per day, or 0.01° per hour. So with my telescope field of view and camera pixel size the trail should be about 33 pixels long, which indeed it was. The rather odd appearance of the trail was due to the planet passing very close to a star near the beginning of the sequence. I verified that by looking at the individual frames.
Canon EOS5DMkII 254mm Newtonian @ 1200mm f/4.8 16 x 15s ISO6400 2011-03-07 20:30:07-21:30:07 UT
From Rookhope 54.8
I also processed the same frames differently so that the planet remained fixed while the stars trailed. Here is a cropped portion of the result:
Canon EOS5DMkII 254mm Newtonian @ 1200mm f/4.8 16 x 15s ISO6400 2011-03-07 20:30:07-21:30:07 UT
From Rookhope 54.8
The blobby nature of the trails is because the early images in the sequence were taken more frequently than every 4 minutes. The processing was done with GRIP's semi-interactive option "Astro combine for comets" on the batch menu. That option is equally useful for most small objects that move relative to the stars.