NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Antoine Couëtte
Date: 2023 Oct 12, 09:34 -0700
Geoff,
and Paul,
In reference also to this recent comment by Paul Hirose " both points increase altitude (not equally) due to refraction, but they remain on the same vertical circle. So refraction does not affect the time when the limb is defective " , you Geoff just mentioned also :
QUOTE
==============================
2023-Oct-14 15:36:08.0 = First touch of Moon with the Sun. (Standard Refraction)
2023-Oct-14 15:36:11.5 = First touch of Moon with the Sun. (NO Refraction)
==============================
2023-Oct-14 18:51:10.5 = Last touch of Moon with the Sun. (Standard Refraction)
2023-Oct-14 18:51:08.5 = Last touch of Moon with the Sun. (NO Refraction)
UNQUOTE
On the first touch, the difference in UT is 3.5s . The closure rate between Sun and Moon Centers is -0.348"/s of time. In 3.5s, the centers become closer by 1.2" .
On the last touch, differnce in UT is 2.0 s. The closure rate between centers is +0.302"/s of time. In 2.0s, the centers distance increases by 0.6".
If we keep assuming that the MOON is a PERFECT SPHERE, and especially at the time of the refracted first touch, I am just puzzled to "see" from your published data quoted here-above that when the refracted limbs are exactly "tangent to one another", their unrefracted counterparts are still separated by 1.2" .
How can that be ?
Anybody with a solid explanation here ?
Kermit
