DETERMINING TEMPERATURE AMPLITUDE AS A FUNCTION OF DEPTH IN THE ATMOSPHERES OF RAPIDLY OSCILLATING AP STARS

We present numerical models based on realistic treatment of the intens ity spectrum (from model atmospheres), and demonstrate that they are c onsistent with Kurtz and Medupe's recent formula in showing that limb darkening is too small an effect to explain the observed sharp decline of pulsation light amplitude with wavelength in rapidly oscillating A p stars. Kurtz and Medupe's formula is shown to be a special form of W atson's earlier general formula for nonradial light variations of a st ar pulsating in any mode (l, m). Using a technique suggested by Kurtz and Medupe we derive temperature semi-amplitude as a function of depth in the atmospheres of alpha Cir and HR 3831, assuming that we can neg lect non-adiabatic effects.