Celestron CI-700 Spécifications télécharger pdf (Page 28)

To calculate the sidereal time approximately, figure out the number of months and days that have

elapsed since the autumnal equinox. Allow 2 hours for each month and 4 minutes for each day in

excess of the months. Add this figure to the Greenwich Mean Time to get a rough estimate of the

Greenwich Sidereal Time. For example, on May 29 at 17h 30m GMT,

months and

days after

the autumnal equinox, figure as follows:

months at 2h per month

8 days at

4m per

day

GMT

Total

16h

Oh 32m

17h 30m

33h 62m

Subtract 24h to obtain the approximate Greenwich Sidereal Time:

GST = 10h 02m.

Sidereal time is the elapsed sidereal interval since the vernal equinox was last on the meridian.

The equinox is the point on the celestial sphere where the sun crosses the equator in the spring.

Sometime called the point of Aries. To obtain a more accurate value of the sidereal time at a

given instant, corrections would have to

made for rotation and precession.

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Celestron CI-700 Spécifications Page 28