Siderial Time : LUSENET : Astronomical_Calculations : One Thread

I have calculated my local sideal time from the equations given on the "Alt Az from RA Dec" page. This time is 1 minute and 10 seconds behind two other sources (my LX200 and SkyMap). Is this the best accuracy that can be expected from these formulas?

-- Mark Presco (, January 23, 2001


When I checked this approximate formula, it seemed to be within decimal fractions of a second of LST. I shall have another look over the Weekend.

Thanks for the warning / feedback.

-- Keith Burnett (, January 23, 2001.

The formula

LST = 100.46 + 0.985647 * d + long + 15*UT

gives answers within 0.7 sec of Web Mica. As I said in the direct e-mail, can you send me the LST value you get from your software together with the UT time, date and the longitude?

-- Keith Burnett (, January 28, 2001.

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