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 .

据说“根据恒星测定的时间”平均比“太阳时间”快4分钟……天文学家使用“根据恒星测定的时间”来测定夜空中已知天体的位置。