Tried to get this one before it disappears over the northern horizon.
At about mag 18, it's fairly difficult to grab. It's also moving pretty fast.
These are 30sec exposures, best 9 looped. The circle at the start should help to spot the asteroid. Even then it's a good test of your vision. Looking at how fast this moves through the background longer exposures may not help as the asteroid may streak.
Captured with a Meade 10"RCX (or ACF, or whatever it's now called) @ f6 (AP 0.75 focal reducer), SBig ST-10XME, no filter. Frames calibrated, aligned and converted to tiff files in CCDStack, curves, levels and animation done in Photoshop.