Near Earth Object 2005 WJ56,
07 January 2008
While looking at the SpaceWeather.com web site on the night of 07 January 2008, I noticed a prediction of a close approach of asteroid 2005 WJ56 on 10 January 2008. (The body is classed an NEO, or near earth object and was predicted to pass within 11 times the distance of the Moon.)
I downloaded the orbital elements from the Minor Planets Centre and loaded them into my "Guide" planetarium software. This showed that 2005 WJ56 was currently very close to β Aurigae and thus easy to find. So I went out to take some images. By the time I had fired up the camera, the asteroid was right on top of the star and I had to wait about 15 minutes for it to emerge from the glare. However I soon picked it up and then took a sequence of 54 thirty-second exposures from 23:03 to 23:33 UT. Each new exposure appearing on the computer screen showed that 2005 WJ56 had moved noticeably and an animation of the images shows its rapid motion against the background stars. The image below, obtained by stacking all the exposures, shows the motion of the asteroid in 30 minutes as a trail.