Analemma over Al Sadeem Observatory, Abu Dhabi

Here’s a thought: if you were to take a photo of the Sun at the same time for several days from the same place throughout the year, would you find it at the same position in the sky?

If the Earth was sitting straight in its axis, and if its orbit around the Sun was a perfect circle, it would.

But because the Earth is tilted at 23.5 degrees towards the Sun, and its orbit slightly elliptical–not to mention the varying orbital speed of our planet–the Sun will be spotted at different points in the sky each day.

When you combine these images of the Sun in one year into one striking photo, a shape similar to the ‘figure of 8’ will form. In astronomy, such is called an analemma–a diagram that shows the Sun’s track throughout the year as seen from Earth. (See Fig. 1)

Fig. 1. Solar analemma over Al Sadeem Observatory in Al Wathba, Abu Dhabi.

Every part of the analemma tells a story, which will depend on where we are on the planet.

Here in the Northern Hemisphere, the bigger loop shows how the Sun traveled in our sky during the winter season (December to early March), while the narrow loop shows where the Sun is during the summer (June to early September).

The equinoxes, meanwhile, are the middle points of the analemma. (See Fig. 2).

Fig. 2. The positions of the Sun during the equinoxes, which are in the middle of the analemma.

Analemmas usually have 52 points which represent the number of weeks in one calendar year, but circumstances like unfavorable weather conditions may affect the imaging process. This is why sometimes analemmas can have noticeable gaps between the dots.

Throughout 2021, our resident astronomer Aldrin Gabuya took a total of 43 photos of the Sun that made up the composite image. These were taken every week around 4:30 in the afternoon, from January 9 to December 25, 2021, with the #Observatory as the foreground element. ⁠

Equipment used: Canon Ra DSLR, Tamron 14-24mm lens, Baader solar filter.⁠