beginning and end of total and annular eclipses, the thin slice of the Sun visible appears
broken up into blobs of light These blobs are called 'Baily's beads' after the British
astronomer Francis Baily (1774-1844). They happen because the edge of the Moon is not
smooth but jagged with mountain peaks. When just one bead is visible, the effect is often
likened to a diamond ring.
Picture shows the annular eclipse of 1984. Baily's beads and the pink chromosphere are visible as the Moon appears to cross the edge of the Sun's disk. Jay M. Pasachoff.