Earlier I wrote:
> I used the solver in xephem version 3.0 to find the zero of the
> equation
> "Sun.HA"+12-"UT"
> (that's "hour angle of the sun" + 12 - "universal time").
> and got the result
> 4/16/1999 3:04:36 UTC
I should have mentioned that I set my place of observation to be
Greenwich for that computation...
It also occurs to me that you may be interested in the error behavior
as you stray from the crossing point. The following was also computed
by xephem using the same formula (and same observation station!). The
unit for EOT is hours. The time is given in UTC; subtract seven hours
for Arizona time (MST).
* Equation of Time
4/15/1999 23:15:00 -0.000634845
4/15/1999 23:30:00 -0.000593328
4/15/1999 23:45:00 -0.00055181
4/16/1999 0:00:00 23.9995
4/16/1999 0:15:00 -0.000468766
4/16/1999 0:30:00 -0.000427248
4/16/1999 0:45:00 -0.000385731
4/16/1999 1:00:00 -0.000344213
4/16/1999 1:15:00 -0.000302809
4/16/1999 1:30:00 -0.000261292
4/16/1999 1:45:00 -0.000219888
4/16/1999 2:00:00 -0.00017837
4/16/1999 2:15:00 -0.000136967
4/16/1999 2:30:00 -9.55628e-05
4/16/1999 2:45:00 -5.4159e-05
4/16/1999 3:00:00 -1.27552e-05
4/16/1999 3:15:00 2.86486e-05
4/16/1999 3:30:00 7.00524e-05
4/16/1999 3:45:00 0.000111456
4/16/1999 4:00:00 0.000152746
Because of wrapping one instance of the equation of time is computed
as just less than 24 hours. Of course this should be -0.0005.
Jim
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| Jim Cobb | 540 Arapeen Dr. #100 | [EMAIL PROTECTED] |
| Parametric | Salt Lake City, UT | (801)-588-4632 |
| Technology Corp. | 84108-1202 | Fax (801)-588-4650 |
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Consultant: n. One who borrows your watch to tell you what time it is
and then keeps the watch.
