A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2020 May 19, 16:30 -0700
Bill Lionheart you wrote: So the discussion Frank and I were having off list is how how to turn this in to a proof that the isoazimuth is a small circle.
I’ve been thinking about this and I’ve come to the conclusion that it’s important here to decide whether we mean ISO Z and ISO Azimuth. E.g. consider Dec 30N and azimuth 060. Z can flip at GHA + 180 , such that Z is still 60, but azimuth is now 360 – 60, so you’ll get a ring which might or might not be a perfect circle. If you stick with ISO Azimuth. Your saying the direction of the star is always at 60 degrees to the meridian, so in this particular case you’d get a spiral. DaveP