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Glossary term: Granulation

Description: In the outer regions of the Sun, currents of hot gas rise up, expand and cool, and then sink back down. This convection process happens within individual cells each about 1500 kilometers across. The hot, freshly risen material at the center of each cell shines brighter than the colder, darker edges where the material sinks back down. This leads to a pattern of bright dots with dark boundaries known as granules. These are temporary phenomena with each granule lasting only a few minutes before the seething mass of convective currents in the Sun disrupts it.

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Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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".