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I guessed wrong as I was reading along, because I thought the pamphlet would
have told George that it was Apparent time.

Does not GHA Sun in the printed Nautical Alamanac that we use in North
America relate directly to position of the apparent sun, rather than  the
mean sun, hence we need to use the EqT to convert from GHA sun to get the
position of the mean sun, for example?  I thought that all the GHA values
for the various bodies in the Almanac related to apparent time, not mean
time?

Jim Thompson
jim2@jimthompson.net
www.jimthompson.net
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> -----Original Message-----
> From: George Huxtable
> I wanted to calculate GHA Aries rather
> precisely. I knew that it corresponded to Greenwich Sidereal Time, but was
> that Greenwich Mean Sidereal Time, or Greenwich Apparent Sidereal Time
> (there's a small difference)? None of my texts on spherical astronomy
> helped, and (though I thought I knew which) I didn't want to guess. But on
> page 59 of the booklet I found - "Table 5 may be used to calculate GHA
> Aries which is equivalent to Greenwich mean sidereal time (GMST)." Just
> what I needed to know.

   

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