Improved hydrodynamic pulsation models for the pulsating extreme helium star V652 Herculis

Abstract New non-linear hydrodynamic models have been constructed to simulate the radial pulsations observed in extreme helium star V652 Her. These use a finer zoning allow higher resolution than previous simulations. Models incorporate updated OPAL and OP opacity tables adopt composition based on best atmospheric analyses date. Key pulsation properties including period, velocity amplitude shock acceleration are examined as function of mean stellar parameters (mass, luminosity, effective temperature). The new confirm that, for large pulsations, strong develops at minimum radius, is associated with phase delay between maximum brightness radius. Using period constrain parameter space one dimension, other used model further, critically discuss observational measurements. Similar may be useful interpretation blue pulsators, which also exhibit pulsation-driven shocks.