Baily's beads

/bay"leez/

spots of light that appear to encircle the moon, resembling a string of luminous beads, visible immediately before and after a total eclipse, caused by the sun's light shining between the mountains on the moon's surface. Cf. diamond ring effect.

[named after Francis Baily (1774-1844), English astronomer who first described them]

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Arc of bright spots seen during a total eclipse of the Sun, named for Francis Baily (1774–1844), the English astronomer who first called attention to them.

Just before the Moon's disk completely covers the Sun, the narrow crescent of sunlight may be broken in several places by mountains and valleys on the edge of the Moon's disk; the resulting spots resemble a string of beads. The "diamond-ring effect" occurs when the very last rays of the Sun to be obscured look like a bright diamond on the solar corona.

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▪ astronomy

      arc of bright spots seen during a total eclipse of the Sun. They are named for Francis Baily, an English astronomer, who first called attention to them. Just before the Moon's disk completely covers the Sun, the narrow crescent of sunlight may be broken in several places by irregularities (mountains and valleys) on the edge of the Moon's disk; the resulting array of spots roughly resembles a string of beads.

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