Wind-Blanketed Stellar Atmospheres

Extract

Radiation scattered by a stellar wind back into the photosphere alters the temperature-depth relation and thus the stellar flux distribution. The fraction of the radiation returned to the star at every wavelength has been calculated using stellar wind models accounting for approximately 10 000 lines. Model stellar atmospheres containing hydrogen and helium, both with and without the assumption of LTE, have been computed allowing for the reflected radiation. For realistic wind and stellar parameters relevant to central stars of planetary nebulae, we obtain a 25% increase in the surface temperature and in the optical brightness temperature, and a 2 order-of-magnitude increase in the flux in the He II continuum.