Glossary term: 绝对星等
Description: 绝对星等是一种测量方法，有两种不同的定义。两者都与天体在一组特殊条件下的亮度有关。定义了绝对星等，我们就可以比较处于不同距离的天体的固有属性。绝对星等与视星等不同，视星等测量的是从观测者所在位置看到的天体的亮度。
对于太阳系外的天体，如恒星和星系，绝对星等的定义是：从 10 秒差距的标准距离处观察天体所得的视星等，且忽略星际消光的影响。通过这个标准化的数字，我们可以比较不同天体的固有亮度。
对于太阳系内的天体，如小行星，绝对星等的定义是：当天体与太阳和观测者都相距一个天文单位，且相位角为0°时，所得的视星等。请注意，若观测者位于地球，则太阳系内的天体永远不可能符合这些条件。但该定义去除了取决于天体和观测者位置的因素，以便我们比较对不同位置的太阳系天体。
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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
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