protostellar

protostellar

1. The absence of protostellar cloud material and the low velocity of the stars shows they could not have been born relatively recently or sailed in from elsewhere in the galaxy.

星系中缺少原恒星物质云团，而且其中的恒星运转速度低，说明恒星不可能是在最近诞生的，也不会是从星系的其他地方飘然而入。

2. The protostellar phase is an early stage in the process of star formation.

这不是核反应造成的，只是重力能量转换成的热动能。