Winds from Hot Stars

TLDR

The review focuses on winds from normal hot stars, including O‑stars, B‑ and A‑supergiants, and central stars of planetary nebulae with O‑type spectra. It introduces advanced diagnostic methods for stellar winds, presents scaling relations for global wind parameters, and discusses their use as extragalactic distance indicators and chemical tracers. The study employs these diagnostics and interprets observations within the stationary, one‑dimensional line‑driven wind theory. The review discusses systematic effects arising from nonhomogeneous structures, time dependence, and deviations from spherical symmetry.

Abstract

▪ Abstract This review deals with the winds from “normal” hot stars such as O-stars, B- and A-supergiants, and Central Stars of Planetary Nebulae with O-type spectra. The advanced diagnostic methods of stellar winds, including an assessment of the accuracy of the determinations of global stellar wind parameters (terminal velocities, mass-loss rates, wind momenta, and energies), are introduced and scaling relations as a function of stellar parameters are provided. Observational results are interpreted in the framework of the stationary, one-dimensional (1-D) theory of line-driven winds. Systematic effects caused by nonhomogeneous structures, time dependence, and deviations from spherical symmetry are discussed. The review finishes with a brief description of the role of stellar winds as extragalactic distance indicators and as tracers of the chemical composition of galaxies at high redshift.