Fitting stellar energy distributions with model atmosphere fluxes has <br /><br /><br />
long been an excellent way to obtain temperatures, gravities and <br /><br /><br />
abundances for stars. However, uncertainties in spectrophotometric <br /><br /><br />
standards and uncertainties in model atmosphere fluxes have <br /><br /><br />
discouraged its widespread use in favour of empirical temperature <br /><br /><br />
calibrations from colors. But in the last few years <br /><br /><br />
new, precise spectrophotometry from 1675 to 10190 Angstroms has been <br /><br /><br />
made available by Gregg, Heap and Lindler from STIS on HST. Using <br /><br /><br />
these data as standards, accurate relative spectrophotometry can now <br /><br /><br />
readily be transformed from most spectroscopic observations. The grids <br /><br /><br />
of model atmosphere fluxes by Munari and Castelli can be used to fit <br /><br /><br />
such observations and determine accurate temperature and gravities and <br /><br /><br />
metallicity estimates for halo stars. I will discuss this work and <br /><br /><br />
show that the fitted temperatures of FGK stars covering a wide range <br /><br /><br />
of metallicities are in good agreement with the new Infrared Flux <br /><br /><br />
Method temperatures of Casagrande et al and support temperatures for <br /><br /><br />
turnoff stars up to 300K hotter than some older calibrations.