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Re: Question to Frank
From: Frank Reed
Date: 2005 Apr 16, 01:52 EDT
From: Frank Reed
Date: 2005 Apr 16, 01:52 EDT
Alex you asked: "In your lunars reducing calculator, which limb of Jupiter is counted, or center?" Center. That's what's recommended in some of the old navigation manuals, and that's how I do it. I try to place the center of Jupiter's disk right on the Moon's limb. (nice couple of days for Moon-Jupiter sights in the Midwest, huh?) And: "BTW, I cannot find any reference to the size of its disc in the almanac, but my impression is that it is very non-negligible." Right now it's about three-quarters of a minute of arc. Yes, it's big. The first month I was on this list (Dec '03), I started a thread with a title of something like "Jupiter is Big" discussing lunars with the largest planet. I find I get exceptionally good results with Jupiter, and I think it has a lot to do with that sharp little disk we see through the sextant's telescope. -FER http://www.HistoricalAtlas.com/lunars