calibration star

例句：

1. 1.The calibration star is used to measure the accuracy of the telescope's alignment.
   校准星用于测量望远镜对准的精度。
2. 2. The astronomers used the calibration star to determine the position of the planet.
   天文学家使用校准星来确定行星的位置。
3. 3. The calibration star was crucial for the successful launch of the spacecraft.
   校准星对于航天器的成功发射至关重要。