Glossary term: 近日點
Description: 太陽系中的大多數天體都是橢圓軌道，太陽位於其中一個焦點。近日點是軌道上天體距離太陽最近的點。從數學上來說，該點標誌著橢圓長軸的一端。其中 "peri" 表示最近點， "helion" 表示太陽。因此，只有當中心體是太陽時纔可以使用這個詞。當中心天體是一顆非太陽恆星時，術語為 "periastron" ；當繞行的中心體是地球時，術語為 "perigee" 。無論中心天體是什麼，通用的術語是 "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
This is an automated transliteration of the simplified Chinese translation of this term
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