A plage is a bright region in the Sun's chromosphere, typically found in and around active regions. Historically, they have been referred to as bright flocculi, in contrast to Solar prominence, and as chromospheric faculae, in contrast to Solar facula.
Etymology
The term is often believed to be poetically taken from the French word for "beach"; however, this is likely a misunderstanding of an 1893 article by Henri-Alexandre Deslandres where the name
facular flames was suggested. In the article, Deslandres also refers to them as
plages brillantes, meaning
bright regions, which became the more commonly used term.
Description
Classically, plage have been defined as regions that are bright in Hα and other chromospheric
. With modern imaging, most researchers now identify plage based on the
photospheric magnetic field concentration of the
Solar facula below. The magnetic field of plage is confined to the intergranular lanes in the photosphere with a strength of around 1500 G, but expands into a volume filling canopy in the chromosphere with a field of around 450G.
It is believed that plage is formed from decaying emerging flux regions, and often acts as a footprint for coronal loops and fibrils, which makes them an important interface for coronal heating.[
]
See also
External links