Baily's beads

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun plural Dots or patches of sunlight visible along the edge of the darkened moon's disk in the seconds before and after totality during a full solar eclipse, caused by sunlight passing through valleys in the moon's uneven topography.

from The Century Dictionary.

• noun See bead.

from the GNU version of the Collaborative International Dictionary of English.

• (Astron.) A row of bright spots observed in connection with total eclipses of the sun. Just before and after a total eclipse, the slender, unobscured crescent of the sun's disk appears momentarily like a row of bright spots resembling a string of beads. The phenomenon (first fully described by Francis Baily, 1774 -- 1844) is thought to be an effect of irradiation, and of inequalities of the moon's edge.