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Baily's Beads

Baily's Beads
Baily's Beads Right before totality begins, the only parts of the Sun's bright face not yet covered by the Moon are those that peek through deep valleys on the advancing lunar limb (edge). Seen through safe solar filters, they look like an arc of bright points. These are called Baily's Beads, after English astronomer Francis Baily, who first described them during a solar eclipse in 1836. They disappear one after another as the Moon continues its advance. Their subsequent reappearance, as the Moon begins its retreat, signals the end of totality. Also visible at the beginning and end of totality are brilliant red arcs, loops, and jets of hot gas. Called prominences, they originate in the chromosphere — the thin middle layer of the Sun's atmosphere — and shine in the red light of hydrogen heated to more than 20,000° Celsius (36,000° Fahrenheit). Reinhold Wittich