NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2010 Apr 5, 04:53 -0700
Jeremy you wrote:
"I will probably give Frank a heart attack, but my longest lunar throw was Ds 115 deg 13.8' to Venus near limb."
Er... huh? Jeremy, where does this come from... what makes you think I have a problem with lunars near 120 degrees?? Out of the hundreds of lunars I've shot (I try to shoot one set every two to four weeks, for no other reason than to get myself thinking about them...), I've shot a couple of dozen between 115 and 125 degrees. Maybe you're thinking of my comments about historical lunars, noting that there was a preference in the logbooks for lunars generally around 90 degrees.
Of this lunar, you wrote:
"The sight error was -0.3' by my Pearson's spreadsheet."
For a Venus lunar? Have you modified the spreadsheet? With Venus, you have to worry about phase effects, semi-diameter, and parallax (all correlated, of course). For those reasons, I usually advise people to avoid Venus for lunars. Interestingly, I have yet to encounter even one case of lunars using any of the planets as the other body in historical logbooks. Anybody have one? I like Moon-Jupiter lunars a great deal for modern lunars experiments, but their success depends on modern accurate ephemerides for Jupiter. There must be some planet-lunars from those late 19th century lunarians in Africa...
-FER
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