cepheid variable 中文意思是什麼
cepheid variable
解釋
造父變星-
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。 -
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。 -
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恆星。 -
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。 -
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，但要得知一顆恆星的光度，我們首先要得知它的距離，這時便須藉助好像視差法等其他量度天體距離的方法。
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