The partial solar eclipse of 4 January 2011

On  the morning of Tuesday, 4 January 2011, a partial solar eclipse was visible in the skies of Egypt. Solar eclipses are among the most magnificent natural phenomena. They occur when the Moon passes between Earth and the Sun. In Alexandria, where the eclipse began at 9:03 a.m., the Moon covered approximately 55% of the Sun’s apparent diameter, at maximum eclipse. The eclipse lasted 3 hours, and was also observable in most of Europe, North Africa, and central Asia.

The eclipse magnitude, the fraction of the Sun’s diameter blocked by the Moon, was greater in Europe. It was 71% in Istanbul, 73% in Paris, 75% in London, and 83% in Copenhagen. In northern Sweden, greatest eclipse was of magnitude 86%. Interestingly, in western and northern Europe, the Sun rose eclipsed, but in central Russia, Kazakhstan, Mongolia and northwest China, the eclipse took place during sunset. 

Through the eclipse, the Moon was around 388,000 km from Earth. Also, Earth was near perihelion, the nearest point to the Sun, along Earth’s elliptical orbit. Earth passes perihelion between 3 and 5 January, at a distance of approximately 147 million km from the Sun. The aphelion distance, Earth’s maximum distance from the Sun, occurs around 4 July, and is approximately 152 million km.

The Planetarium Science Center (PSC) organized a festivity featuring a public observing session, to observe the eclipse, from the BA Plaza. The participants observed the eclipse through two refractor telescopes, a Sunspotter and solar filters. The Sunspotter is a simple, innovative type of telescopes, designed for solar observations. The observation began at 8:40 a.m.

Caution:Never observe the Sun with your eyes, or through the telescope, or any other optical aid. The Sun can only be observed through special optical instruments. Observe the Sun only under the supervision of an astronomy specialist.

Following the observation, PSC Astronomer Aymen Ibrahem, conducted a public lecture, titled “Eclipses of the Sun and the Moon”. The lecture featured intriguing facts on eclipses and the nature and characteristics of the Sun and the Moon.

Aymen Mohamed Ibrahem

Senior Astronomy Specialist