Description: 主序是赫罗图上一个细长的恒星群，其上的恒星处于主要的氢聚变演化阶段。除质量最小的恒星以外，其他恒星在完成核心氢聚变后都会脱离主序，开始进入巨星阶段的演化。主序上的恒星通常被称为矮星，以区别于巨星。主序上的热恒星比主序上的冷恒星更亮。最热的恒星消耗氢的速度很快，因此通常只在主序上停留几百万年。像太阳这样的恒星在主序上的时间约为百亿年，而较冷的恒星在主序上保持稳定氢聚变的时间甚至更长。

Related Terms:

• 矮星
• 巨星
• 赫罗图
• 氢聚变
• 恒星演化

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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