I've always been fascinated with astronomy and the relationship of the sun to our seasons on earth. Since we've been stuck in the clouds and cold weather for much of the week, I thought you might enjoy reading about what the sun is up to behind the gray curtains of cloud cover here in the Tri-State.
As you know, the days are getting longer as we approach the start of spring and will continue to get longer right up to the first day of Summer in mid June. The sun follows a predictable and beautiful pattern through the year. This figure 8 pattern is called the analemma. The middle of the figure 8 is where the equinoxes occur, both spring (vernal) and fall (autumnal). On these days, the sun is directly over the equator and we get approximately 12 hours and day and 12 hours of night.
On the longest day of the year, the summer solstice, the sun is directly over the Tropic of Cancer, and is as far north as it will get during the year. On the flip side, the sun is directly over the Tropic of Capricorn on the winter solstice in December, our shortest day of the year.
Below is an account of imaging the analemma by the photographer, Anthony Aviomemitis, whose images appear in this blog entry.
"Strange as it may seem, only seven times has someone ever managed to successfully image the solar analemma as a multi-exposure on a single piece of film. For those not familiar with the term, an analemma is the figure "8" loop that results when one observes the position of the sun at the same time during the day over the course of a year. Due to the earth's tilt about its axis (23.45°) and its elliptical orbit about the sun, the location of the sun is not constant from day to day when observed at the same time on each day over the course of a full year. Furthermore, this loop will be inclined at different angles depending on one's geographical latitude.
Since the analemma is considered one of the most difficult and demanding astronomical phenomenon to image, I immediately set out on such a marathon during the summer of 2001 by pursuing a complete set of analemmas from 08:00:00 to 17:00:00 UT+2 (hourly intervals) as well as the special case of the perfectly vertical analemma on the meridian (12:28:16 UT+2). For complete details and analysis concerning the analemma on the southern meridian, the interested reader is referred to my article in Coelum Astronomia (Vol 60: 71-74, Feb/2003). The project's successful completion provided various firsts including the first analemma ever imaged in Greece; the first image ever of the perfectly vertical analemma; the first analemma(s) ever imaged during a single calendar year; the first to ever image more than one analemma; and the first to ever capture two analemmas on a single piece of 35mm film. As noted elsewhere, more men have walked on the moon than have successfully photographed the analemma"
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