Convection zone
A stellar layer where energy moves mainly through circulating plasma: hotter material rises, loses heat, and cooler material sinks.
Convection: Heat transfer by the bulk movement of a fluid or deformable material. Stellar convection is this general transport process operating in plasma.
Stellar structure: The internal arrangement and physical state of a star, shaped by gravity, pressure, energy generation, and transport. Convection zones are regions within this larger structural profile.
Solar dynamo: The process by which flows and magnetic fields inside the Sun sustain and regenerate its magnetic activity. Convection supplies moving, electrically conducting plasma that helps drive the solar magnetic cycle.
Conduction: Heat transfer through microscopic interactions without bulk movement of the material. It transports energy differently from the large-scale plasma flows in stellar convection.
Adiabatic lapse rate: The rate at which temperature changes with height in a fluid parcel moved without exchanging heat. The parcel’s temperature change helps determine whether displacement grows or is reversed.
Hydrostatic equilibrium: A balance in which pressure gradients support a fluid against inward gravitational force. This balance sets the pressure and density background through which convection develops.
Stellar magnetic activity: Magnetic phenomena in stars, including spots, flares, and cycles of magnetic-field variation. Convection can combine with rotation to generate the fields behind this activity.
Radiative zone: A stellar region where energy is transported mainly by photons diffusing through matter. It is the principal alternative to a convection zone inside many stars.
Mixing-length theory: A model that estimates convective energy transport by treating fluid elements as traveling characteristic distances before dissolving. Stellar models use it to approximate convection that cannot be resolved directly.
Radiative transfer: The transport of energy through emission, absorption, and scattering of electromagnetic radiation. Radiative transport competes with convection in carrying stellar energy.