Sun surface features

These are some of the numerous terms for features and activity on the Sun's surface (and above) with a bit about how they are interrelated. The Sun's surface features and activity are complex and our understanding is still limited and this outline is incomplete and simplified. Within the photosphere:

• sunspot - cool, dark (i.e., less bright) spot, where magnetic field lines emerge.
• facula - bright spot.
• granule - visible bump: convection bubble reaching the surface, occurring across all the Sun's surface.
• supergranule - like a granule but on a much larger scale: a single supergranule encompasses many granules.

Within the chromosphere:

• spicule - small jet from photosphere into chromosphere.
• Moreton wave - shock wave traveling across the surface, triggered by some types of activity (below).
• plage - bright region of chromosphere, often near sunspots.

Within the corona:

• coronal hole - thin, cool region of corona that emits less X-rays.
• solar prominence - detectable projection into corona, plasma made to glow from magnetic field lines extending into the corona.
• coronal loop - loop-shaped solar prominence which is typical: magnetic field lines do not end, and generally are loops from within the Sun out into the corona and back into the Sun.
• flux rope - coronal loop projections twisted around each other like a rope. It can be ejected during some types of activity (below).
• magnetic arcade - aligned row of coronal loops forming a "tunnel", perhaps a spiraling loop shaped like a spring.
• helmet streamer - large coronal loop, with the top of the arch not slender, but stretching far out from the Sun: the stretch can be a full Sun-diameter; helmet streamers are the typical features of the corona seen during total eclipses.

Beyond:

• heliospheric current sheet - extends through solar system.

Solar activity:

• solar flare - the term is sometimes used merely to imply a brightening event, and sometimes is meant to imply a solar eruption.
• solar eruption - an event that ejects material, which could be called a heavy blast of solar wind. Often associated with a solar prominence.
• coronal mass ejection (CME) - a very large solar eruption; the term is also used for the material ejected.
• solar particle event (SPE) - effect of some solar eruptions to Earth: particles such as protons reaching Earth vicinity and possibly Earth atmosphere. Effects on Earth depend upon size of the eruption and the direction in which it is pointed.
• geomagnetic storm - effect of some solar eruptions to Earth, including radio and electronic interference, often including auroras.
• solar weather and space weather - general terms for effects of some solar eruptions to Earth, to spacecraft and the rest of the solar system.