ON THE EFFECTIVE TEMPERATURES, SURFACE GRAVITIES, AND OPTICAL-REGION FLUXES OF THE MAGNETIC CP STARS

Abstract

We determined effective temperatures and surface gravities for five MCP stars using ATLAS9 metal-rich model atmospheres, optical region spectrophotometry, and H gamma profiles. The predictions of these models fit the continua significantly better than do those of previous generation ATLAS models. They can even match the 5200 Angstrom 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 5200 Angstrom features. The 4200 Angstrom and the 6300 Angstrom features are not reproduced in the models. The relationship between the strength of the 5200 Angstrom feature and metallicity was also explored using spectrophotometric and photometric indices.