{{Short description|Bright region in the Sun's chromosphere}} thumb|In this near true color photograph, taken through a narrowband hydrogen-alpha filter, plages are visible as overexposed patches. A '''plage''' {{IPAc-en|p|l|eɪ|dʒ}} 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 dark flocculi, and as ''chromospheric faculae'', in contrast to photospheric faculae.<ref>{{cite book | title=Advances in Geophysics | volume=8 | chapter=Indices of Solar Activity | first1=R. Grant | last1=Athay | first2=Constance S. | last2=Warwick | year=1961 | isbn=9780080568362 | page=30 | publisher=Elsevier Science | editor1-first=Helmut E. | editor1-last=Landsberg | editor2-first=J. | editor2-last=Van Mieghem | chapter-url=https://books.google.com/books?id=4iBkdCd0dEUC&pg=PA30 }}</ref>
==Etymology== The term {{wikt-lang|fr|plage}} 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 {{lang|fr|plages brillantes}}, meaning ''bright regions'', which became the more commonly used term.<ref name="pietrow22">{{cite thesis |type=PhD |last=Pietrow |first=A.G.M. |date=2022 |title=Physical properties of chromospheric features: Plage, peacock jets, and calibrating it all. |publisher=Stockholm University| url=https://www.diva-portal.org/smash/record.jsf?aq2=%5B%5B%5D%5D&c=10&af=%5B%5D&searchType=LIST_LATEST&sortOrder2=title_sort_asc&query=&language=en&pid=diva2%3A1651858&aq=%5B%5B%5D%5D&sf=all&aqe=%5B%5D&sortOrder=author_sort_asc&onlyFullText=false&noOfRows=50&dswid=5451 | doi=10.13140/RG.2.2.36047.76968}}</ref>
==Description== Classically, plage have been defined as regions that are bright in Hα and other chromospheric emission lines. With modern imaging, most researchers now identify plage based on the photospheric magnetic field concentration of the faculae 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.<ref>{{cite journal |title=Inference of the chromospheric magnetic field configuration of solar plage using the Ca II 8542 Å line |doi=10.1051/0004-6361/202038750|bibcode=2020A&A...644A..43P |last1=Pietrow |first1=A. G. M. |last2=Kiselman |first2=D. |last3=de la Cruz Rodríguez |first3=J. |last4=Díaz Baso |first4=C. J. |last5=Pastor Yabar |first5=A. |last6=Yadav |first6=R. |journal=Astronomy and Astrophysics |year=2020 |volume=644 |page=644 |arxiv=2006.14486 |s2cid=220055853 }}</ref><ref>{{cite journal |title=Stratification of canopy magnetic fields in a plage region. Constraints from a spatially-regularized weak-field approximation method |doi=10.1051/0004-6361/202038754|bibcode=2020A&A...642A.210M |last1=Morosin |first1=Roberta |last2=de la Cruz Rodríguez |first2=Jaime |last3=Vissers |first3=Gregal J. M. |last4=Yadav |first4=Rahul |journal=Astronomy and Astrophysics |year=2020 |volume=642 |page=642 |arxiv=2006.14487 |s2cid=220055552 }}</ref>
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.<ref name="pietrow22" />
==See also== * Solar cycle * Solar spicule * Solar granule
==References== {{reflist}}
==External links== *[http://www.daviddarling.info/encyclopedia/P/plage.html Encyclopedia of Astrobiology, Astronomy & Spaceflight: Plage]
{{the Sun}}
Category:Stellar phenomena Category:Solar phenomena
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