Lifecycles of Stars
What is a nebula?
The layer of the Sun's interior that is closest to the surface.
What is the convective zone?
The phase of the solar activity cycle characterized by a disorderly magnetic field, when open field lines (coronal holes) and closed field lines (coronal loops) can be found at any latitude on the Sun?
What is solar maximum?
The sharp boundary where the supersonic solar wind drops to subsonic speeds upon first encountering Earth's magnetosphere.
What is the bow shock?
A large, glowing ball of plasma that generates heat and light from nuclear fusion in its core.
What is a star?
A sphere of dust and gas that has begun to produce heat and light due to gravitational collapse.
What is a protostar?
The layer of the Sun's interior where nuclear fusion occurs.
What is the core?
A burst of electromagnetic radiation from the Sun, triggered by tangled magnetic field lines breaking and reconnecting.
What is a solar flare?
The region filled with subsonic solar wind plasma just outside of Earth's magnetic field.
What is the magnetosheath?
High-energy particle radiation from the Sun, where the particles have been accelerated to high speeds either impulsively (near solar flares) or gradually (by CME shock waves).
What is a Solar Energetic Particle (SEP) event?
The slowly-cooling, carbon core of what once was a low-mass, main sequence star.
What is a white dwarf?
The type of light emitted by the faint, reddish chromosphere.
What is the H-alpha emission line?
The shape of the Sun's magnetic field at its most orderly, during solar minimum.
What is a dipole magnetic field?
The physical process that allows particles from the solar wind to enter Earth's magetosphere.
What is magnetic reconnection?
The balanced state of inward pressure due to gravity equalling outward gas pressure.
What is hydrostatic equilibrium?
A star with hydrogen fusing into helium in its core.
What is a main sequence star?
The layer of the Sun's atmosphere that includes filaments, prominences, and plage.
What is the chromosphere?
A high-energy eruption of plasma launched from the Sun that can travel at speeds much higher than the solar wind.
What is a CME?
The boundary where the inward pressure of the solar wind is balanced by the outward pressure of the Earth's magnetic field.
What is the magnetopause?
The physical process where the plasma at the Sun's equator rotates faster than the plasma at the Sun's poles, causing the magnetic field to "wind up."
What is differential rotation?
The end state of a high-mass star with a high-mass core.
What is a black hole?
The layer of the Sun characterized by a "random walk" of photons, due to numerous collisions with the densely-packed plasma?
What is the radiative zone?
A rope of plasma that is explosively released from the Sun during magnetic reconnection, and can become the core of a CME.
What is a filament eruption?
The two regions of high-energy particle radiation in Earth's inner magnetosphere.
What are the Van Allen radiation belts?
A shock front that propagates on the surface of the Sun, and can be set off by solar flares.
What is a Moreton wave?