Terme du glossaire : Granulation
Description : Dans les régions extérieures du Soleil, des courants de gaz chauds s'élèvent, se dilatent et se refroidissent, puis redescendent. Ce processus de convection se produit à l'intérieur de cellules isolées d'environ 1 500 kilomètres de diamètre. La matière chaude qui monte vers la surface au centre de chaque cellule brille plus que les bords plus froids et plus sombres où la matière redescend. Il en résulte un motif de points brillants avec des limites sombres, appelés granules. Il s'agit d'un phénomène temporaire, chaque granule ne durant que quelques minutes avant d'être perturbé par la masse bouillonnante des courants convectifs du Soleil.
Voir ce terme dans d'autres languesStatut du terme et de sa définition : La définition initiale de ce terme en anglais a été aprouvée par un·e spécialiste de la recherche en astronomie et un·e spécialiste de l’éducation La traduction de ce terme et de sa définition n'ont pas encore été aprouvées
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".
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Dans d'autres langues
- Arabe: حبيبات الشمس
- Allemand: Granulation
- Anglais: Granulation
- Italien: Granulazione
- Japonais: 粒状斑 (Liens externes)
- Népalais: कणिकीकरण
- Portugais brésilien: Granulação
- Chinois simplifié: 米粒组织
- Chinois traditionnel: 米粒組織
Media associé
High-resolution image of the surface of the Sun
Légende : This high-resolution image of a small portion of the outermost visible "surface" of the Sun (the photosphere) covers an area 36,500 by 36,500 km. It was one of the first images taken by the Daniel K. Inouye Solar Telescope, as part of the telescope's Science Verification Phase. Each of the cells that are visible is about the size of the US state Texas, or of France, or of Afghanistan, or of Somalia. In the brighter centers of these cells, plasma from the underlying regions rises to the surface, cools off, and then sinks down again at the location of the darker lanes delineating the cells. In these dark lanes we can also see the tiny, bright markers of magnetic fields.
Crédit : NSO/NSF/AURA
Lien vers les crédits
License: CC-BY-4.0 Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Icônes
Close-up view of a sunspot
Légende : This image of a sunspot was taken by the Daniel K Inouye Solar Telescope (DKIST), operated by the U.S. National Science Foundation. It was taken only in light with a wavelength of 530 nanometers, within the greenish-yellow part of the visible spectrum.
The picture reveals the detail of the spot's structure and the Sun’s photosphere. The dark central region, known as the umbra, is surrounded by a lighter area called the penumbra with radially elongated features stretching towards the umbra. Note that the umbra and penumbra here are not the same as the umbra and penumbra that occur during an eclipse.
The sunspot measures approximately 5000 kilometres in diameter, roughly equivalent to the east-west span of China. While the umbra appears black, it is actually hot and bright. It only appears dark because it is a few thousand kelvin cooler than the surrounding solar photosphere. Surrounding the sunspot, granulation patterns of plasma are visible on the photospheric surface of the Sun.
Crédit : NSO/NSF/AURA
Lien vers les crédits
License: CC-BY-4.0 Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Icônes



