For the galaxy and the andromeda nubula, they do not form a pair of galaxies completely isolated from all others . 对银河系和仙女座星云来说，它们并不构成与所有其他星系完全孤立的一对星系。
The magnitude of the turbulence then follows directly from the observed line with if the nebular gas temperature is known . 如果已知星云气体的温度，则湍流的大小可直接从观测的谱线宽度得出。
The great nebula is a cloud of glowing gas centered on four hot, blue stars located about 1, 500 light-years from the earth . 这个大星云是以离地球大约1500光年的四颗很热的蓝星为中心的发光气体云。
The temperature of the nebula in some places may never have risen high enough to evaporate pre-existing micron-sized interstellar grains . 星云中某些地方的温度可能从未升高到足以使原有的微米级大小的星际尘埃变成气体。
These calculations can be compared with the chemical analyses of meteorites in an attempt to ascertain the conditions in the nebula at the time of their formations . 这些计算可与陨星的化学分析相比较，从而推断在它们形成时星云中的条件。
Radio astronomers are now able to synthesize the response of a partially filled aperture of large diameter and thus to map variations in nebular brightness . 射电天文学家现在已经能够把部分充满的大直径孔径进行综合，从而描绘出星云亮度变化图。
Some celestial bodies similar to galactic nebulas but without any luminosity sometimes reveal their presence as dark patches obscuring the light of stars beyond them . 某些与银河星云相似但不发光的天体，有时看来象块黑色补丁，遮住了周围的星光。
The most obvious advantage is that because of their inability to scatter appreciably, nebular radio waves completely and genuinely delineate the distribution of nebular gas . 因为星云对射电波的散射很小，所以最明显的优点就是能够全面而真实地勾画出星云气体分布的外貌。
One can be found at the center of the crab nebula ，在蟹状星云中心便有一颗。
