astronomical

• There are differences between historical and astronomical numbering of years .
  在历史的年代数目和天文年代数目之间存在差别。
• In astronomical situations, the natural line width is seldom directly observed .
  在天文学研究中，谱线固有宽度很少能直接观测到。
• A powerful laser and astronomical telescope are used for this measurement .
  在测量时使用了一台功率强大的激光器和一台天文望远镜。
• It is hardly necessary to extract its value every time from an astronomical yearbook .
  没有必要每次都从《天文年历》中查出它的值。
• There is the time of the summer solstice an astronomical twilight lasting throughout the whole night .
  夏至时天文晨昏蒙影持续整夜。
• The unsteady air is the most dangerous source of disturbance for astronomical photography .
  不稳定的空气便是天文照相最危险的干扰源。
• He is most noted for the creation of the first astronomical theory of the heavenly motions .
  他最出名的工作是创立了天体运动的第一个天文学说。
• The error in azimuth must be controlled by astronomical observations for azimuth(and longit ude) .
  方位误差必须观测天文方位角（及经度）来控制。
• Commencing in 1474, mathematical, astronomical and astrological works appeared in printed form .
  从1474年起，数学、天文学和占星术的著作开始印刷出版了。
• The mirror of an astronomical telescope forms at its focal point an image of a star on the axis of the mirror .
  天文望远镜把在镜轴上的星体成象在焦点上。