22 December 2009


If you took a photo of the sun at exactly the same time every day, from the same position on the ground, using the same composition with respect to the horizon and nearby objects, the resulting pattern of solar positions over the course of the year would describe a lopsided figure 8, called an analemma (see image above). The horizontal/vertical position of the figure 8 will be determined by the time of day you choose for recording solar position in the sky. By working backward, one can deduce with reasonable accuracy the time of year, from the sun's position at that assigned time.

Recently NASA's website APOD (Astronomy Picture of the Day) posted a most unusual analemma variation -- one which was timed to record a total solar eclipse. The resulting, very special figure is called a tutulemma -- a word coined by the photographers based on the Turkish word for eclipse (see image below). As always, click on an image to enlarge it.

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