The purpose of this update is to alert potential observers to a probable technical difficulty in monitoring this event visually.

The prediction as given by Edwin Goffin gives a magnitude drop for this event of around 0.9. However, it is unclear as to how this value was derived. The asteroid is predicted to be around 10.47 at the time of the event while the only data available for the star (GSC 6846 748) gives a Photographic magnitude of 11.02. Brian Loader recently visually inspected the star and suggests that the Visual magnitude will not be grossly dissimilar to the Photographic one (ie. around 11.0)

Assuming that the asteroid will be around magnitude 10.5 at the time of the appulse and that the star is in fact magnitude 11.0, the correct magnitude drop for this event will be around 0.5 of a magnitude. This is generally regarded as being too small a difference to be reliably detected by visual means and as a result renders this event virtually unobservable for visual observers. Naturally, observers with the appropriate photometric equipment can still make useful observations and are strongly encouraged to do so.