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Solar and sidereal time

The stars rise 3m 56s earlier each night compared with solar time. This is due to the motion of the Earth in its orbit round the Sun.

Solar day. The Earth makes one rotation compared with the Sun. 3 minutes 56 seconds longer than a sidereal day.
Sidereal day. The Earth makes one rotation compared with the distant stars. 3 minutes 56 seconds shorter than a solar day



 
 
 
© Keith Gibbs and John Bourne 2016