sidereostat

例句：

1. 2.例句：1. The sidereal time is the time it takes for the Earth to orbit the Sun.
   恒星时是地球绕太阳运行所需的时间。
2. 2.The sidereal time is important for astronomers to measure the distance between stars.
   恒星时对于天文学家测量恒星之间的距离非常重要。
3. 3.The sidereal time is also used to calculate the date when a planet crosses the ecliptic plane.
   恒星时还用于计算行星穿越黄道平面的日期。