This makes space telescope invaluable for identifying a rare class of pulsating stars , called cepheid variable stars embedded within m100 ' s spiral arms 這對于從m100的旋臂中分辨出暗藏的造父變星有著莫大價值。
Astronomers made observations of cepheid variable stars [ pictured above ] ? pulsating stars used to measure vast distances ? in the virgo and other clusters to establish the expansion rate and the universe ' s age 天文學家用哈勃觀測到仙女星座和其它星群中的造父變星(如圖) ,以確定宇宙的膨脹速度和宇宙的年齡。