The sidereal year is not used to construct a calendar .
恒星年不用于编制年历。
You can see for the sidereal day , the earth has gone through one complete rotation ( with respect to the background stars ) .
你可以看到太阳日就是地球自转完整一圈的时间（参照某颗背景恒星）。
So , the tropical year is a little bit shorter than the sidereal year .
因而回归年要比恒星年要短一些。
A sidereal day is shorter than a mean solar day by 3 minutes and 56 seconds .
恒星日比平均太阳日短三分五十六秒。
Sidereal time is said to be on average 4 minutes more per day , than solar time astronomers use sidereal time to locate known objects in the night sky .
