Astrophotography by Anthony Ayiomamitis

Solar Image Gallery - Analemma (13:00:00 UT+2)

Incredible as it may sound, only seven times has someone ever managed to successfully image the solar analemma as a multi-exposure on a single piece of film. An analemma is basically 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. As a result of the earth's tilt about its axis (23.5) 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 a period of twelve months. Furthermore, this loop will be inclined at different angles depending on one's geographical latitude.

As suggested by the relatively few number of successfully completed analemmas (seven total including the pioneering photo in 1979), the imaging of the sun over local skies during the course of twelve months is considered one of the most difficult and demanding astronomical phenomenon to image. The analemma presented below is one of TEN analemmas completed during a marathon started in 2001 in an attempt to document the complete range of analemmas from sunrise to sunset (see here). It is further unique as it represents the seventh of eight analemmas ever imaged during a single calendar year and also the ninth analemma ever imaged in Greece.

Note: The animated motion of the analemma sun below was constructed from the original film negative containing the 46 single exposures. Its purpose is to illustrate the wandering motion of the sun during twelve months and whose net motion is described by the analemma curve or "figure eight". The bottom apex point represents winter solstice whereas the first solar disk to the immediate upper-left is the start of January and where we observe the gradual and steady increase in the sun's altitude from day-to-day. This increase continues into February and March and, by mid-April, we have reached the cross-over point between the two loops. The sun continues its steady rise across local skies but is now on the right portion of the upper loop and which peaks at the apex point of the upper loop on summer solstice. It is at this point that the sun will now start another gradual and steady pace but this time with declining altitude and where, during July and August, it will traverse the left side of the upper loop. We reach the cross-over point once again but this time at the end of August with the sun now losing altitude at a greater pace while it is now on the right side of the lower loop and which will climax with the winter solstice and the apex point once again.

Note: As noted elsewhere, more men have walked on the moon than have successfully photographed the analemma (see S&T, Dec/2003: 73).


Image Details
Analemma with the Temple of Poseidon (450-440 BC)
Imaging Details
Body:
Sun

Mass:
332,900 x Earth

Mean Eq Diameter:
109.1 x Earth

Distance:
147 million km

RA / Dec:
02h 13m 05s /
+13 23'


Diameter:
32.03'

Magnitude:
-26.8
Date:
Jan 06, 2004 - Dec 20, 2004
13:00:00 UT+2


Location:
Athens, Greece

Equipment:
Canon A-1
Canon FD 24 mm @ f/11
Fuji Super HQ 100
Baadar Solar Filter ND5


Exposures:
1/30 sec
46 multiple exposures +
  1 foreground exposure


Software:
Photoshop V6

Processing:
Layers
Resampling (25%)
JPG Compression