NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brad Morris
Date: 2013 Jan 31, 13:47 -0500
Chief Franklin
If you will examine the 1849 issue of Bowditch, you will find Table VIII, which is the right ascensions and declinations of some of the fixed stars along with the annual variation, starting from the beginning of the year 1830. Its not 1500, but its roughly 200 years closer than today!
Of course, SHA=360-RA, so you get the terms you are looking for.
You can use this data to extrapolate backwards & forwards in time. I suggest that you first extrapolate forwards to today, to see what precision you obtain. Once you understand how it projects forward, you can then extrapolate backwards.
This will not be a highly accurate method, but considering that the intended use is plotting on the base of the 2102D, it may very well suit your purposes.
Regards
Brad Morris
I am working on a project and need information on SHA & dec changes
for stars. I want to replot some star on my 2 minute star finder to recheck
sighting postions on the old mill in Newport RI. Mill may have been built
year 1500. How much star changes? The noticed change SHA & Dec is interesting.
Any old date year will give clue if not 1500.
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