On the effective temperatures and surface gravities of superficially normal main sequence band B and A stars

Effective temperatures and surface gravities for 48 main sequence band B and A stars were found by matching optical region spectrophotometry and Hgamma profiles with the predictions of ATLAS9 solar composition model atmospheres. When these values were compared with those found using Stromgren uvbybeta photometry based on ATLAS6 model atmospheres, we found a difference (photometry-spectrophotometry) of 25 +/- 118 K for 29 stars with 8000 K less than or equal to T-eff less than or equal to 10 050 K compared to 76 +/- 105 K for 14 stars with 10 050 K less than or equal to T-eff less than or equal to 17 000 K. The surface gravity scales are in agreement. These stars are sufficiently hot that their effective temperatures and surface gravity determinations are unaffected by discrepancies due to the choice of Mixing-Length or Canuto-Mazzitelli convection theories.