Occulting Light (Oc)

A rhythmic light in which each period of light is longer than the total darkness within the same cycle.

The light appears mainly on with regular eclipses and may show single, group or composite-group occultations. Its chart abbreviation is commonly ‘Oc’ followed by any group, colour and period information. It differs from a flashing light, which is dark longer than lit, and an isophase light, whose light and dark durations are equal. Identification should combine rhythm with colour, period, sector and position rather than rely on one observed eclipse.

Abbreviation

Oc

Class of Light

Single Occulting

Illustration

Period Shown