Glossary term: 近日点
Description: 太阳系中的大多数天体都是椭圆轨道，太阳位于其中一个焦点。近日点是轨道上天体距离太阳最近的点。从数学上来说，该点标志着椭圆长轴的一端。其中 "peri" 表示最近点， "helion" 表示太阳。因此，只有当中心体是太阳时才可以使用这个词。当中心天体是一颗非太阳恒星时，术语为 "periastron" ；当绕行的中心体是地球时，术语为 "perigee" 。无论中心天体是什么，通用的术语是 "periapsis" 。
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Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
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".
