This is a combined image overlapping two 15 second exposures, taken at 20:22:44 UT (long trail on the right) 20:49:24 UT (short trail on the left) respectively. North is up and the asteroid was moving from south (bottom) towards north (top).
The instrument used was the University of Athens Observatory 0.40m f/8 Cassegrain reflector with a SBIG ST-10XME CCD camera and a f/6.3 focal reducer, resulting in a 25x17 arcminutes field of view.
The two images were taken at different equatorial coordinates, thus the background is the superposition of two stellar fields. Note that the two exposures have the same duration, but the trail has different length, as a consequence of the variation of the projected angular velocity of the asteroid during flyby.