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A third major astronomical event takes place this month during dawn on Saturday, 31st May. From Northern Ireland it will be a partial eclipse of the Sun. The previous two events this month were a transit of the planet Mercury across the face of the Sun on 7th May and a total lunar eclipse on 16th May.

A solar eclipse is caused by the Moon passing directly between the Earth and the Sun, with the Moon's shadow falling on the Earth. Saturday's solar eclipse will be annular from northern Scotland and Iceland. The apparent diameter of the Moon will be somewhat less than the diameter of the Sun, so the Sun will never get completely covered by the disc of the Moon but the outer edge of the Sun will remain visible right around the edge of the Moon. At maximum eclipse, a ring of light will shine around the Moon’s limb.

From Northern Ireland, at maximum eclipse, just over half the Sun's disc will be covered by the Moon. The eclipse will be well under way when the crescent Sun rises in the northeast at about 5:00 am on Saturday. The eclipse will end at about 5:38 am when the Sun will be about 4 degrees above the horizon.

For best viewing conditions, select a site with as low a northeastern horizon as possible. One should always be careful never to look at the Sun with or without optical aid as permanent eye damage could result. It is best to use a projection system where the Sun's image is focused through a small telescope or binoculars onto a sheet some distance from the eye lens, being careful not to look at the Sun through the instrument.

FOR FURTHER INFORMATION CONTACT: John McFarland at Armagh Observatory, Tel: 028-3752-2928; FAX: 028-3752-7174; e-mail jmf@arm.ac.uk

Last Revised: 2003 May 28th
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