No outburst bright enough to observe visually has occured since 1999 July. Although it reaches to 13.5 mag in summer, only southern people can observe it. Borrelly In the Northern Hemisphere, it appears at dawn at 10 mag in late July, then reaches to 8 mag in autumn. It will appear at dawn in June at 14 mag, then will fade gradually. Only southern people can observe it.
Northern people can never see it again.
It will appear at dawn in July as 15.5 mag. Because it is far away, it keeps brighter than 16 mag until August. It hardly faded out since the perihelion passage in 2000 June. But no observation has been reported since Jan. 5. So the current brightness is uncertain.