Grids for the determination of effective temperature and surface gravity of B, A and F stars using uvby β photometry

Synthetic colours and indices for uvbyβ photometry, calculated by Relyea & Kurucz and Schmidt from line-blanketed model stellar atmospheres by Kurucz, are compared with observed colours and indices for B, A and F stars of known T_eff and log g. Adjustments are needed to bring synthetic uvby colours and β indices into agreement with observed values; these empirically corrected synthetic values are presented as two-dimensional |$(\beta,\,{c}_{0})\,\text{or}\,({a}_{0},\,{r^{\ast}})$| grids which can be used to determine T_eff and log g. The synthetic β indices appear insensitive to the metal abundance of a model atmosphere. Results for three Am binaries suggest that the grids are sufficiently insensitive to metal abundance to be used for determining T_eff and log g for Am stars.