The asteroid now known as 8225, and provisionally known as 1996 QC was discovered at COAA on 16th August 1996 by Chris Durman and Bev Ewen-Smith using the 0.5m telescope and the Starlight Xpress CCD imager. It was moving slowly to the west in Sagittarius, close to the Ecliptic and coming to the end of its retrograde loop.
Comparing two CCD image frames, the movement of the 18th magnitude object became obvious over a period of about half an hour. This animation (if you have Netscape 2 or later) shows the asteroid on the discovery images.
COAA CCD images
Further images were obtained on the following night and the precise measurements were emailed to the IAU Minor Planet Center.
The MPC responded with the provisonal designation 1996QC.
Measurements were repeated every night (easy with so many clear nights at COAA!) for a couple of weeks and eventually Gareth Williams at the MPC was able to compute an orbit for 1996QC which took in some previously unattributed observations from 1981 and 1986. The orbital elements published in Minor Planet Circular MPC27723 therefore represent observations at three oppositions over a period of 15 years.
The asteroid has a period of 5.4 years and remains close to the Ecliptic and within the usual asteroid belt. It does, however, have an unusually high eccentricity which makes it rather faint for most of its orbit. It was lucky that it was close to perihelion, close to opposition and moving relatively slowly near the end of its retrograde loop when it was picked up in the COAA 0.5m telescope.
From the apparent magnitude of the asteroid, it appears to be a rocky fragment about 5km in diameter.
More measurements were made towards the end of 1997 and eventually, in January 1998, the IAU allocated the permanent designation 8225 to the object.
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