September 13, 2021

Noon Analemma Sundial

 

Noon analemma sundial, Cerrillos Hills State Park, Cerrillos, New Mexico, 2021.


Sundial gnomon (at top of south-facing circular opening).


In this simple sundial, the sun's image is projected through a south-facing pinhole (gnomon) creating a bright spot on the structure's floor or sill. As the days and seasons pass, the spot changes position as the sun rises higher or lower in the sky. The figure-eight pattern (analemma) on the floor marks the spot's position at noon at different times of the year.


Sundial analemma.

Photos by I. Peterson

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