The tropical regions of Africa enjoyed a ringside seat to the second and last solar eclipse of 2013 today (Sunday, November 3, 2013). Those in Africa saw either a total solar eclipse or a deep partial solar eclipse in the afternoon hours on November 3. Much of the rest of the world saw a partial eclipse on November 3. Over the Atlantic Ocean, just as the eclipse began, it was an annular or ring eclipse. Almost immediately thereafter, it changed into a total eclipse. That’s why people are calling this a hybrid eclipse.
Where in Africa is the total eclipse being seen? The only total eclipse of the sun in all of 2013 passes over equatorial Africa (Gabon, Congo, Democratic Republic of the Congo, Uganda, Ethiopia, Kenya and Somalia) in the afternoon hours on November 3, 2013. The moon’s dark shadow (umbra) first touches the Earth’s surface at sunrise in the Atlantic Ocean around 1000 kilometers east of Jacksonville, Florida, at 11:05 Universal Time (UT). The moon’s dark shadow then goes eastward across the Atlantic Ocean and equatorial Africa. Some three and one-third hours after its initial landing on Earth, the moon’s dark shadow leaves the Earth’s surface at sunset from Somalia, Africa.
However, as seen from any one spot in Africa, the total eclipse of the sun lasts – at most – just a little over one minute. Totality lasts for 67 seconds in western Gabon (2:51 p.m. local time), and only one second long in Somalia as the moon’s shadow starts its liftoff from Earth.
Why is the eclipse on 2013 November 3 called a hybrid solar eclipse?. If the new moon aligns with the sun so as to pass directly in front of the solar disk, it’s called a central eclipse. A central eclipse can either be a total eclipse of the sun, or an annular, or ring, eclipse of the sun. During a total eclipse, the moon is close enough to Earth to totally cover over the solar disk. During an annular eclipse, the moon lies too far away from Earth to completely cover over the solar disk. In that case, a thin ring – or annulus – of sunshine surrounds the new moon silhouette.
A hybrid solar eclipse refers to a solar eclipse in which some sections of the central eclipse path are annular while other parts are total.
For the November 3 eclipse, if you are at just the right spot in the Atlantic Ocean, you’d see a four-second annular eclipse at sunrise. According to Jean Meeus and Fred Espenak, the eclipse changes from annular to total in just fifteen seconds, and the remainder of the approximate 13,600-kilometer central eclipse track remains total.
On the other hand, the International Astronomical Union and the U.S. Naval Observatory – using slightly different parameters – call it a total solar eclipse.
Technically speaking, by Meeus and Espenak’s calculations, the 2013 November 3 is a hybrid (annular-total) solar eclipse. However, the eclipse changes from annular to total almost immediately after the start of the central eclipse, and moreover, the moon comes progressively closer to Earth throughout the duration of this eclipse.
Bottom line: The moon’s shadow swept across Earth on Sunday, November 3, creating a total eclipse of the sun. The best place to observe the total eclipse was Africa. This is the second and last solar eclipse of 2013. Those in Africa saw either a total solar eclipse or a deep partial solar eclipse in the afternoon hours on November 3. Over the Atlantic Ocean, just as the eclipse began, it was an annular or ring eclipse. Part total, part annular. That’s unusual, and it’s why people are calling this a hybrid eclipse.