Description: 太阳常数是指距离太阳一个天文单位（地球到太阳的平均距离）处，垂直于太阳光线方向的单位面积上接收到的来自太阳的平均电磁辐射量（光能）。目前，它在真空（地球大气层外）中约为每平方米 1361 瓦。虽然它不是一个物理常数，但在数百年的时间里变化不到 0.2%。然而，地球的轨道是椭圆形的，因此在地球距离太阳的位置上，其流量密度会有7%的变化。随着太阳的演化，它正在慢慢变得更亮，因此在数十亿年的时间里，这个数值会显著增加。

Related Terms:

• 电磁辐射
• Sun

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

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