Annular Solar Eclipse of 2010 January 15

On 15 January, 2010, an annular eclipse of the sun was visible in southern part of India. In contrast to a total solar eclipse, an annular eclipse occurs when the moon is slightly less in angular size than the sun so that it cannot completely cover the sun. This happens when the orbital position of moon is further away when its shadow falls on the Earth. It is the antumbral shadow that causes the eclipse, as the umbral shadow does not reach earth. During an annular eclipse, the Sun is covered by the apparently smaller Moon and thus it appears like a ring (annulus) and hence the name.

For the 15th January annular eclipse, the path of the annularity (track of the antumbral shadow) was a 300km wide corridor which began at 05:13:54 UT over central Africa, passing over the Indian Ocean crossing southern India, and ending on the Chinese Yellow Sea coast at 08:59:01 UT. The maximum duration of annularity was 11m 08s and occurred somewhere in the Indian Ocean.

In India, Dhanushkodi in Rameshwaram was the best site to view the eclipse, with Kanyakumari being the next best site. Although, partial eclipse was visible on a much broader range, which included Bangalore as well, we selected Kanyakumari in order to watch this celestial event in its full form. Adding to it, the fact that the next total solar eclipse over India will be on 20th March 2034 only was another reason to go.

Our team consisting of 4 senior scientist and 4 students were stationed at Kanyakumari to capture the annularity.
We started preparing for the event at 9am on the day of the eclipse. The lawn of the hotel we were staying was the best place for observing since it was an isolated location and far away from the unusual crowd gathered on that day in Kanyakumari. We had two DSLR cameras, one SLR camera and a camcorder which were mounted with appropriate filters to take pictures of the sun. Since the annular phase is very bright with photospheric light outshining the corona, experimental observations could not be done. But, the shear joy of observing the eclipse motivated us to grab as much as we can.

By 10am, our cameras were all ready and we already started taking pictures. A sunspot region was clearly visible on the solar disc. As predicted, the first contact happened at around 11:14am with the clouds giving way for a unhampered view of the sun being slowly covered by the moon. In the beginning, the sky was very clear with just some passing clouds. But as the partial eclipse progressed towards annularity and just before the second contact (1:17pm) until sometime after the third contact (1:27pm), the clouds played spoilsport and the cameras had a though time to get a clear photograph. Luckily, we were able to capture the mid-annularity (1:22pm), with the perfect ring shape. The annularity lasted for about 10mins. The temperature slightly dropped and the weather became very pleasant. Through the clouds we could see the big hole in the sky with a brightly lit rim. This was an experience of a lifetime.

THE NEXT LUNAR AND SOLAR ECLIPSE PAIR OF 2009-2010

IIA Astronomers observe the Total Solar Eclipse of July 22, 2009 from China

Eclipse images taken by IIA from different locations within India

Last updated on: February 20, 2024