The phase of 18.76 hours seems to be holding true: http://www.lolife.com/astronomy/hd189735/phase.jpg V-R=0.17 or so at phase 0.25. SIMBAD reports B-V=0.23. Taken together these imply a spectral type of A5. This seems consistent with TASS V-I=0.34. The star is perhaps slightly later than the HD type of A2? Cheers, Michael K.