Book "Light prodigy in St Peter's Dome"

This small book is a report of an extraordinary discovery, a “prodigy” which takes place at sunset on St Peter’s Dome on the day of the spring equinox. The charm of this sight consists in admiring the basilica against the light and observing how the sun beam crosses two of the sixteen windows on the drum of the dome. This phenomenon – witnessed by the photographs in this small volume – lasts about thirty seconds, during which a “luminous star” seems to light up in the cornice of the Michelangelesque dome.