Glossary term: 地平
Description: 地平线是将天空与地球表面分开的边界线。在地球上的任何位置，我们都只能看到地表有限的一部分。我们所能看到的部分与我们所不能看到的部分之间的分界线通常称为地平线。在天文学中，这一定义细化如下：我们在地球上的某一位置处，先用铅垂线找出向下的方向，接着将垂直于下方的平面定义为地平面。地平面与天球的交点即为我们的天文本地地平。地平坐标系利用地平面来定义天体在天空中的位置。我们看到天体的视线与地平面之间的夹角称为天体的高度角；视线在地平面上的投影与真北之间的夹角称为天体的方位角。
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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".
