Observed parameters of 0 type stars

A review is made of the determinations of the effective temperature, luminosity and masses of 0 type stars. This also involves the status of the comparison of the observations with non-LTE plane-parallel models, which can then be used to derive other parameters about the stars. For most 0 type stars, there seems to be good understanding of the temperature scale and overall comparison to models. For a significant minority, the Of stars and supergiants, there are still uncertainties in the models due to the necessity of including spherical geometry effects and stellar wind dynamics.