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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Interstellar distance
From: Fred Hebard
Date: 2005 Sep 12, 16:03 -0400
From: Fred Hebard
Date: 2005 Sep 12, 16:03 -0400
On Sep 12, 2005, at 3:46 PM, Bill wrote: >> Bill has offered some code to do the job, but perhaps Mike wishes to >> understand the problem and how to solve it, rather than paste in >> another's >> code. >> >> My first word of advice, to Mike and to many other listmembers, is to >> acquire a copy of "Astronomical Algorithms", by Jean Meeus. > > George > > Thanks for the thorough coverage, and the correct spelling of Meeus. > My > spreadsheet did not attempt to deal with Sun or moon angular > separation from > bodies. I tended to use the moon and Franks lunars to determine > sun/moon, > moon/star distances. Not yet good enough to do Sun/star shots ;-) > > Therefore, your latest posting was of great interest to me, and starts > to > give me a handle on dealing with the Sun and moon separation angles. > Thanks > again. > > I did send along some of the background used in constructing the > spreadsheet > to Mike et al, which included Meeus formulas, as well as text captures > of > postings by you and Frank some time back on the subject including > formulas. > As you have pointed out, there are several ways to skin that cat, and > my > spreadsheet addresses only one of them. > > Bill > > Bill, Your spreadsheet may be able to handle the star-star distances without much difficulty. It's just that the "moon" (and "sun") would have zero semi-diameter and parallax. The refraction is the same regardless of body (unless the extra step of adjusting the refraction for semi-diameter is undertaken, but here, again, the zero semi-diameter should account for that). Fred