A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Peter B
Date: 2023 Nov 19, 22:51 -0800
as asked, data is as follows :
PA Zet Cap 64.55 degrees
Altitudes, including Dip & Refraction
Peacock 16d 49'
Alnair 33d 57'
The Zet Cap altutude of 28d 22' previously given is corrected altitude ( clear of dip & refn )
NOTE : these results are only given to nearest 1' of angle because of several factors.
1. the picture scale gives a resolution of a little over 2' af angle per pixel in the centre
2. the lens distortion I estimate to reach about 6 pixels in the extremities, but the pattern is not known
3. the Dip used is 3'. See the Suwarrow beach picture shows the island is maybe 5 ft above high water
and the star picture was likely taken on a tripod or table for steadiness for long exposure, so perhaps 10 ft above S/L
It is good luck that Peacock is at the centre if the star picture. If it was not, the PA's calculated would have unknown
Over to you then.