Astrophysics & Particle Physics-APPC 2026

Stellar Winds are steady streams of gas and charged particles expelled from the outer atmospheres of stars. Stellar winds are important in stellar evolution, mass loss, enrichment of the interstellar medium, and star-forming region dynamics. They differ in intensity and content based on the star type, age, and mass.

Unfortunately, low-mass stars, such as the Sun, have solar winds, made up of protons, electrons, and alpha particles streaming outward into space. These winds determine the heliosphere, affect planetary atmospheres, and are responsible for space weather events like geomagnetic storms and auroras. High-mass stars, such as red supergiants and Wolf-Rayet stars, have strong radiation-driven winds that can strip off large fractions of stellar mass during their lives and thus modify their evolution and final fate, for example, supernova explosions or neutron star formation.Stellar wind research encompasses the understanding of the physical driving mechanisms of the outflows, i.e., radiation pressure, magnetic fields, and thermal expansion. Observations in multiple wavelengths—from radio to X-ray—enable astronomers to determine wind velocity, density, and composition.

These are essential for modeling stellar feedback, by which stars imprint on nearby gas, set off or quench star formation, and control the chemical evolution of galaxies.Stellar winds also play a role in astrophysical processes like bow shocks, circumstellar nebulae, and mass transfer in binaries. Their coupling with the interstellar medium enriches the galaxy in heavier elements, which affect later generations of stars and planetary systems.Stellar winds give astrophysicists a window into stellar lifecycles, the processes of mass loss, and mechanisms behind high-energy cosmic events. Knowledge of these winds is necessary for explaining observations of near stars and distant stellar populations, which helps in getting a complete picture of how stars sculpt their surroundings and the cosmos at large.