pulsating variable造句

Pulsating variables are stars that are continuously expanding and contracting and therefore show variations in brightness
例如脉动变星就是恒星本身不断膨胀收缩，造成光度亦出现相应的变化。
Pulsating variables vary periodically , but for some stars , there may be sudden changes in their brightness . such kinds of stars are called eruptive variables . they include
：脉动变星的光度会周期性地改变，但有一些恒星的光度会在毫无先兆下变得光芒万丈，这种恒星包括新星和超新星皆统称为爆发变星。
It's difficult to find pulsating variable in a sentence. 用pulsating variable造句挺难的