Like Bruce Pipes, I accidentally caught an asteroid on my data from the 2008 Chiefland Star Party. The asteroid can be seen shining through the Cirrus Nebula between Maia and Electra in M45! You can see the multi-colored dashed line since the exposure included LRGB frames. Using the Harvard Minor Planet Checker database, I identified this as mainbelt asteroid “122700 2000 SA20” at magn. 18.3. It was discovered by LINEAR (link attached) at Socorro, New Mexico on September 23, 2000. I linked my image to The Sky and added 2000 SA20 to the database and input my exposure times. A gif animation of the exact track from The Sky is shown above. Any doubt that 2000 SA20 is our object?! Nope!
http://en.wikipedia.org/wiki/Lincoln_Near-Earth_Asteroid_Research – LINEAR