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Re: Eclipses and longitude
From: Ross Henderson
Date: 2026 Aug 23, 22:48 -0700

If using cosine formula, sin h=sin(phi)sin(delta)+cos(phi)cos(delta)cos(t),am I right in assuming that t = arccos(sinh-(sin(phi)sin(delta))x(secant(phi)(secant(delta)) I'm using Norries. And the sign for t is by observation, or is there a formula for calculating sign of t?

Another use of the old secant?!

Thanks for your help

Ross

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