C - cepheid 中文 - EN166

cepheid (variable) 【天文學】造父變星。

cepheus
Except those celestial objects of several hundred light years , astronomers rely primarily on cepheid variables for measuring distances of celestial objects . using ground telescopes to gauge cepheid variables enable us to directly measure celestial objects within 20 to 30 millions light years . for more distant stars , other methods have to be used 除了幾百光年內的星體外，天文學家很主要倚靠測量造父變星來計算天體的距離，利用地面望遠鏡測量造父變星，可直接給出約二三千萬光年內星體的距離，而對于更遙遠的星體，天文學家便要借助其他方法，但這些方法還是需要利用造父變星來作校正。
We have to use some other methods to measure the luminosity or equivalently the absolute magnitude of the cepheid variable . since we can readily measure the apparent magnitude of a cepheid variable , to measure the luminosity means measuring the distance . we use some distance measurement methods , for example , parallax , to determine the relation 要弄清這個關系，我們要知道不同造父變星的光度和光變周期數據，量度光變周期當然不是問題，但要得知一顆恒星的光度，我們首先要得知它的距離，這時便須借助好像視差法等其他量度天體距離的方法。
The longer the period , the brighter the star is . thus , by measuring the period of a cepheid variable , we know its absolute magnitude , hence , we can tell how far it is away by comparing with its apparent magnitude 所以，只要知道某一造父變星的周期，我們便可得知它的絕對星等，只要和它的視星等作比較，便可以求得它和我們的距離。
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。
Cepheid variables are dimmer than the type i supernova . as a result , the supernova allows us to measure the distances of galaxies further away , but it happens much less often I型超新星比造父變星光亮，所以能夠量度更遙遠星系的距離，唯一缺點是不經常有i型超新星爆發。
Since delta cephei was one of the earliest members of a special kind of variables being discovered , all variables in this family are called cepheid variables or simply cepheids 星的中國名稱為造父一，由于它最早被發現的一種新變星類別，所以這類變星皆稱為造父變星。
One of the key project of hubble s telescope is to gauge as many cepheid variables as possible in more distant galaxies up to 65 millions light years 哈勃太空望遠鏡的一個重點計劃，就是要測量更多更遠星系中的造父變星遠達
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。
Double - mode cepheid 雙模造父變星
Cepheid variable stars are stars whose brightness changes at regular periods 造父變星是一種光線按規律周期發生變化的恒星。
Cepheid variable is the foundation of this ladder ，而造父變星便是這階梯中不可或缺的其中一環。