sidereal speed?

[67champ]

What is sidereal drive speed? What speed is used to track the moon? thanks.

[[1ponders]]

A drive that moves a telescope at sidereal rate moves the scope round the Right Ascension axis at the rate that stars move across the sky. If a telescope was able to move a full 360 degrees around the RA axis it would take about 4 minutes less than 24 hours. This is the difference between a sidereal day and the mean solar day of 24 hours. This is why stars/constellations appear to rise a bit earlier every night (4 minutes earlier) using the same time each night.

The moon moves at a different rate across the sky compared to that of the stars. This is the lunar rate. If you have a computerized tracking system on your scope it will often have the lunar rate built in. If you watch the moon carefully it appears to rise about 1 hour 8min later each night.

[syzygy]

The sidereal day is 3 minutes 56 seconds shorter than the mean solar day (clock time). The moon is much slower. It's own motion moves it a degree east every 2 hours.

Regards,
Chris