In 2002 I tried to monitor the magnitude drop of this star under non ideal sky conditions. The lightcurve is here but the precision of the measurements is poor.
In 2006 I tried again.
The planet circling this 8mag star was found by a group of french astronomers. In the evening of the 25 Oct 2005 it was predicted a transit of the b-planet. Initially the sky was cloudy but then it cleared. I observed 4 hours, capturing the 0,03 mag drop of the brightness of the star. This drop lasted 1 h and 40 m.
The star HD189733 is just East from the Dumbell nebula (North=up; East=left).