NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Antoine Couëtte
Date: 2013 Jul 3, 08:48 -0700
RE# 1 : http://fer3.com/arc/m2.aspx/18-june-2013-lunar-distance-Hirose-jul-2013-g24555
RE# 2 : http://fer3.com/arc/m2.aspx/18-june-2013-lunar-distance-Hirose-jun-2013-g24541
Hello Paul,
I have to confess that I am bit lost:
In RE# 2, I can read that you published the Moon and Altair coordinates as follows :
QUOTE
USNO MICA 2.0
106 34 28.48 (= 106 34.4747), calculated from geocentric apparent places with respect to true equator and equinox at TT = 03:31:07.1.
12 49 1.478 -8 12 48.78 Moon
19 51 28.291 +8 54 23.41 Altair
Delta T = 32.184 + 35 - 0.0661627, the last figure from the USNO Earth
Orientation database search page
http://maia.usno.navy.mil/search/search.html
UNQUOTE
and,
In RE# 1, for (apparently) exactly the same date and time "[2013-06-18 0330 UT1, 67.1178 delta T, DE406 ephemeris, Hipparcos second reduction]" I can read that you published the Moon and Altair coordinates as follows :
QUOTE
From Lunar3 I get Moon coordinates
-2.44969548e-003 -5.24187596e-004 -3.58294080e-004 au, or
192° 04′ 40.973″ -08° 08′ 21.886″
and Altair coordinates
4.59325899e-001 -8.74784757e-001 1.54179599e-001 au, or
297° 42′ 09.913″ +08° 52′ 09.188″
UNQUOTE
I can see that both sets of results are quite different.
For your information, I am computing:
For the MOON:
12h49m01.422s (192°15'21.323") and -8°12'50.265" , which differs by 1.7" from MICA (and stays well whithin my limitation of +/- 4")
and,
For ALTAIR:
19h51m28.289s (297°52'04.334") and +8°54'23.397" , which which differs by 0.03" from MICA,
*******
As a conclusion, I would think that your earlier published results are the most accurate ones.
Please be so kind as to bring me some light here.
With many thanks in advance,
As an ever untamed delta-T publishing fan, I am remaining,
Most computationally yours,
Kermit
Antoine M. Couëtte
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