This image shows an active region of the Sun. The National Solar Observatory, Sacramento Park, CA, made it using one of several types of telescopes. Information about the Sun’s activity is used to support of space weather forecasts. NSO has equipment that acquires solar images in the hydrogen-alpha line (once per minute), in continuum (once every ten minutes), and in line-of-sight magnetic fields. Images are passed through an automatic image-processing pipeline and are subsequently analyzed and displayed using various software tools. The areas marked, "plage" represent an area of brightnes. Filiments are gas clouds above the Sun's surface.
Click on image for full size
Image courtesy of the National Solar Observatory at Sacramento Peak
Above the photosphere is the chromosphere,
a region about 2500 kilometers thick. Just prior to and just after
the peak of a total solar eclipse ,
the chromosphere appears as a thin reddish ring. The conspicuous
color of the chromosphere (compared to the mostly white corona) led to its
name (meaning ``color sphere.'')
The chromosphere is most easily viewed in emission
lines such as Hydrogen alpha, where bright regions known
as plages, and dark features called filaments are visible. Filaments
are the name given to prominences
when they are seen on the solar disk.
Spicules are visible in the chromosphere on the limb (the edges) of the
sun. They are jets of plasma shooting up from supergranule
boundaries. While small compared to the sun, these plasma jets are
actually the size of earth!
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