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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Star-to-star distance for sextant calibration?
From: Paul Hirose
Date: 2019 May 20, 15:50 -0700
From: Paul Hirose
Date: 2019 May 20, 15:50 -0700
On 2019-05-19 19:32, Tony Oz wrote: > In a 43-year-old (Soviet) book I found a table with several star-to-star distances (Kocab, Alioth, Capella, Vega, Alpheraz and Altair, all referenced to Polaris). There is a table with corrections for refraction. Instructions given are enigmatic (even for a Russian reader). Refer to the first (Kochab) table. At 1976 Jan 1 the distance from Kochab to Polaris is 16°34.67', which is consistent with the "D" value of the table. With Lunar 4.4 I calculated the decrease due to refraction for several apparent altitudes, and at culmination. Latitude (φ) = 30°. The table values are in parentheses. 20° 0.82' (.7) 30° 0.28' (.3) 40° 0.52' (.5) upper culmination 0.78' (.8) lower culmination 2.11' (2.3) Temperature 10 C and pressure 1010 mb.
