Baily's beads

American  

[bey-leez] / ˈbeɪ liz /

plural noun

1. 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.

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Baily's beads British  

/ ˈbeɪlɪz /

plural noun

1. the brilliant points of sunlight that appear briefly around the moon, just before and after a total eclipse

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Baily's beads Scientific  

/ bā′lēz /

1. A discontinuous, beadlike pattern of sunlight visible along the edge of the darkened Moon's disk in the seconds before and after totality during a full solar eclipse. The pattern is caused by light shining through the uneven lunar topography silhouetted along the curved edges of the disk. Baily's beads are named after British astronomer Francis Baily (1774–1844), who first observed them in 1836.

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Etymology

Origin of Baily's beads

Named after Francis Baily (1774–1844), English astronomer who first described them

Example Sentences

Baily’s beads are formed when sunlight shines through the valleys and craters of the Moon’s surface, and are only briefly visible when an eclipse is beginning or ending.

From BBC • Sep. 12, 2024

Just before totality, viewers can also spot flashes of light — known as Baily’s beads — along the circumference of the moon.

From Los Angeles Times • Feb. 23, 2024

These are called Baily’s beads, after the astronomer who first described them.

From Salon • Aug. 19, 2017

A total solar eclipse is the most stupendous sight in nature: the abruptly darkening sky; Baily's beads, glints of sunlight shining through lunar valleys; the dazzling diamond-ring effect; the spiky, pearly solar corona.

From Nature • May 23, 2017

The black drop seems to bear a family resemblance, so to speak, to the phenomenon of Baily's beads.

From Astronomy of To-day A Popular Introduction in Non-Technical Language by Dolmage, Cecil Goodrich Julius