Mati Morel has provided a comparison star sequence (email to vss-participants egroup) which is now incorporated the AAVSO charts for the nova.
The nova has faded to below V=13 by Aug 18 and is considered likely to be a “fast nova”. This makes observations all the more urgent.
The nova has received the official designation V2672 Oph
Nova Ophiuchi 2009, discovered 2009-08-16