from
The Collaborative International Dictionary of English v.0.48
Baily's beads \Bai"ly's beads\ (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.
[Webster 1913 Suppl.]