Hello JOHN,
I think the difference between my reported time and that given by Jim
Morrison converges very closely the same value, if as I suspect, Jim has
incorporated DeltaT in his calculation i.e., the difference between
Dynamical Time and Universal Time. I know that I have not, still on the
punch sheet though! I don't have the exact current value handy but it is
on the order of a minute of time. Therefore, I would say you have two
values that are quite close to one another. The interesting thing to me
is that like Jean-Paul I too use the VSOP87 periodic terms to calculate
solar position however the two EoT zero times based upon it are quite
different, I guess I would suspect a different computation method of the
EoT itself.
Regards,
Luke Coletti
John Carmichael wrote:
>
> Several people wrote me with their calculations of when EOT=0. I hope they
> don't mind if I sumerize their answers for you here.
>
> Jim Cobb: 4/16/1999 3:04:36 UTC (xephem version 3.0)
> Luke Coletti: 4/16/1999 0:40:00 UT (Solar Calculator)
> Jean-Paul Cornec: 4/16/1999 1:06:04 UT (VSOP87)
> James Morrison: 4/16/1999 0:40:57 UT (?)
>
> As you can see, all the calculations are different. I assume this is due to
> the different calculating methods that were used. Surely there can only be
> one correct answer.(Or should I use the average time of all the answers?)
>
> Thanks again to Jim, Luke, Jean-Paul, and James for taking the time to do
> the calculations.
