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Re: Sun sights during an eclipse: "bad limb" calculation
From: Frank Reed
Date: 2023 Oct 7, 05:50 -0700
From: Frank Reed
Date: 2023 Oct 7, 05:50 -0700
Geoff H, you wrote:
"the Elev of the Moon was out by more than half a degree."
Anytime you see a roughly one degree difference in the Moon's altitude, compared to your expectations, think parallax. Some data sources list the Moon's geocentric altitdue as the "true" altitude. Others list the topocentric (observer-local) altitude. It's not rare to get tripped up on this, and it's happened to me more than once! :) The JPL Horizons data for the Moon's altitude is undoubtedly correct. It's just that it's not the sort of altitude that you expected it to be.
Frank Reed
