diamond-ring effectA bright flash of sunlight from a conspicuous Baily's bead sometimes very briefly observed, together with the solar chromosphere, at the Moon's limb just before or after totality during a solar eclipse.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
diamond-ring effect[¦dī·mənd ′riŋ i‚fekt]
A phenomenon observed just before and after the central phase of a total solar eclipse, in which the last Baily's bead glows brightly compared with other visible features, and the solar corona forms a band that is visible on the rest of the lunar edge.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.