A heavy star at the upper end of the main sequence has a rather different later history . 在主序上端的大恒星具有很不相同的晚年史。
Hydrogen to helium conversion provides the prime source of energy for stars on the main sequence . 由氢向氦的转变是主序星能量的主要来源。
As these luminous and massive stars exhaust their hydrogen fuel, they begin to depart from the upper end of the main sequence . 当这些亮而且质量大的恒星耗尽了氢燃料时,它们就开始从主星序上端脱离。
And stars in this region are called main sequence stars ,位于此区域的星则称为主序星。
In the h - r diagram below , our sun is now in the main sequence 在以下的赫罗图中,太阳正位于主序上。
Tams , terminal - age main sequence 终龄主序
The main sequence stage lasts for a long time in the life of a star 对于大质量的恒星,由于它们的核反应速率很快,大约
Zero - age main sequence 零龄主星序
It takes about 0 . 1 to 100 million years for the cloud to become a main sequence star 这个收缩过程需要十万至一亿年,才能演化成一颗主序星。
After it reaches the main sequence , the star will stay there for millions to billions of years 一般恒星会在主序星阶段逗留一百万至一百亿年。