Taurus Hill Observatory was able to measure the transit of the XO-1b in the night 26./27.8.2006. This is a quite good result, because the target star was so low in the northern sky. Despite that the observing team Veli-Pekka Hentunen, Markku Nissinen and Harri Haukka got a really clear lightcurve.
Conditions were quite good. Humidity was quite high, but it wasn’t a problem (RH was about 80%). Temperature was also quite nice, +12 celcius.
In differential photometry we used (C1) GSC 2041-186 and (C2) GSC 2041-976 as comparison stars. The used filter was clear filter (c)and exposure time was 60 s. Each data point in the figures is the average of the five succesive exposures. Magnitude error bars are the standard deviation of these five exposures.