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Re: Star-to-star distance for sextant calibration?
From: Michael Bradley
Date: 2019 May 20, 11:05 -0700
From: Michael Bradley
Date: 2019 May 20, 11:05 -0700
Hi Tony
The tables heading D looks like a set of refraction correction for the particular star's difference to Polaris. The stars are arranged in a spoked wheel form so as to offer a range of stars, one of which will be close to under Polaris at any given time. D=16.5 probably refers to differences between Kochab and Polaris (90 - Kochab Declination = 16.5 ) and so on through the stars in the star diagram.
The values look like refraction corrections, always +ve when differences are measured vertically up to Polaris. Than there may well be separate sets of values for different angles from the vertical under Polaris.
After that it's all Russian to me.
Michael Bradley
