星系

Such stars indicate their luminosities by their periods of variability and are used to tell the distances of distant galaxies.

通过研究这类恒星亮度的周期性变化，可以得知遥远星系的距离。

A dim foreground star and a bright star located much farther away -- whose light can be diminished by interstellar gas -- can be hard to tell apart because they appear to have similar luminosities as stars in our own galaxy.

一个光线暗淡的前景星星和一个位于远的多地方的光亮的星星-－－其光芒可能由于星际气体而被削弱－－两者之间很难区分，这是由于在我们自己的星系内它们都发出的是相同的光度。

Eventually, billions of years from now, they will merge into a single, more massive galaxy.

最后，在未来的几十亿年内，它们回渐渐的融合，从而形成一个共同体——一个新的、更大的星系。

The most convincing evidence of black holes comes from research into binary star systems.

黑洞最有说服力的证据来自对双星系的研究。

A spokesman said, in the vicinity of our universe, some galaxies being combined are most fertile in creating new ones.

一位发言人说：&在我们附近的宇宙中，有些正在融合的星系体造就新恒星的能力是最高的。&

Shara's research interests include stellar collisions, novae and supernovae, and the populations of stars that inhabit star clusters and galaxies.

夏拉的研究兴趣包括恒星碰撞、星与超新星，以及星团和星系内恒星的数目分布。

However, the Chinese did map the stars with great thoroughness and kept detailed records of eclipses, comets, novae and meteors which are still useful to modem astronomers.

然而，中国人绘制了详尽的星系图，并且完整地记录了日月蚀、彗星、新星和流星的情况，这些记录对今天的天文学家也是很有用的。

Shara's research interests include stellar collisions, novae and super novae , and the populations of stars that inhabit star clusters and galaxies.

夏拉的研究兴趣包括恒星碰撞、星与超新星，以及星团和星系内恒星的数目分布。

HST-1 is so bright that it is outshining even M87's brilliant core, whose monster black hole is one of the most massive yet discovered.

HST-1是如此的亮以致于它比M87明亮的星系核心更亮（参看上一楼和下一楼的图——译注），而M87核心的黑洞是已知最大质量的黑洞之一（另一个在M81核心，剩下的几个50亿以上的还存在许多争议——译注）。

And receding galaxies could mean only one thing.

后退的星系只可能表明一件事

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。