1995A&A...296..467A

We determined effective temperatures and surface gravities for five MCP stars using ATLAS9 metal-rich model atmospheres, optical region spectrophotometry, and Hγ profiles. The predictions of these models fit the continua significantly better than do those of previous generation ATLAS models. They can even match the 5200A broad, continuum features in three stars where this feature is of moderate strength. A synthesized spectrum of one of these stars, HD 43819, suggests that this feature is at least due partially to differential line blanketing. However, problems remain in fitting the optical region energy distributions of stars with stronger 5200A features. The 4200A and the 6300A features are not reproduced in the models. The relationship between the strength of the 5200A feature and metallicity was also explored using spectrophotometric and photometric indices.