, April 16, 1999 7:18 PM
Subject: Re: EOT=0
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
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
Hello John and all,
Well, I quite agree with everyone, I had read
the mails a bit quickly (it was late here). EOT =
0 for a certain moment in UT, and that moment can
correspond to different days according to the
longitude and time zones. It is the same thing as
the seasons occurence
[EMAIL PROTECTED] wrote:
Hello John and everybody on this list,
I don't want to extend this discussion endlessly
, but I am surprised to read that the value of
EOT depends on longitude. [...]
I believe John was referring to the (local civil) date (and time) of
the occurrence of
moment of the event, EOT=0, is absolute
and occurs at the same time everywhere. The date, however, may be different
due to longitudinal time zone differences.
I guess what I need is the AVERAGE four dates for The United States. Do you
think that it is ok to stick with: April 15, Jun. 14, Sep 1
Andrew James contributed:
Please can someone point me to an explanation of exactly how the mean
sun is derived?
There is a clutch of very useful time-related definitions in the opening
chapter of Whitaker's Almanack.
Tony Moss
to do with longitude. Taking again Jim
Cobb's formula, for any place on Earth :
UT = Local Solar Time - EOT + 12 + Longitude(west
is positive).
The time when EOT = 0 is :
UT = Solar Time + 12 + Longitude; or
UT = Local Sidereal Time - AD + 12 + Longitude
;and :
UT = Greenwich Sidereal Time
nothing to do with longitude. Taking again Jim
Cobb's formula, for any place on Earth :
UT = Local Solar Time - EOT + 12 + Longitude(west
is positive).
The time when EOT = 0 is :
UT = Solar Time + 12 + Longitude; or
UT = Local Sidereal Time - AD + 12 + Longitude
;and :
UT = Greenwich Sidereal
John,
Here's another for you, though I am unsure of its accuracy! I was playing
just now with the NASS Dialist's Companion and changing the date and time
to find when their calculation of EoT turns to zero.
For the longitude of Greenwich (and, as it happens, 52 Lat and with other
corrections
My own computations (derived from VSOP87) give
16th April at 01h 06m 04s UT.
Jean-Paul Cornec
--
De : Phil Pappas [EMAIL PROTECTED]
A : sundial@rrz.uni-koeln.de
Objet : WHEN DOES EOT=0
Date : mardi 13 avril 1999 17:20
Hello all:
Does anybody know the exact time (UT) when
/planet/astrodir/astrolab.htm
- Original Message -
From: Phil Pappas [EMAIL PROTECTED]
To: sundial@rrz.uni-koeln.de
Sent: Tuesday, April 13, 1999 11:20 AM
Subject: WHEN DOES EOT=0
Hello all:
Does anybody know the exact time (UT) when the Equation of Time equals
zero
this April 15th
Hello all:
Does anybody know the exact time (UT) when the Equation of Time equals zero
this April 15th (or is it the 16th)?
Thanks
John Carmichael
Tucson
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 +
Hello Phil,
Per my Solar Calculator, I get a zero for the EoT between 00:39UT and
00:40UT on April 16. The solar declination values are 09d53m43s and
09d53m44s respectively.
Regards,
Luke Coletti
Phil Pappas wrote:
Hello all:
Does anybody know the exact time (UT) when the
13 matches
Mail list logo
