* Astronomy

In ancient Roman religion, Summanus was the god of nocturnal thunder, as counterposed to Jupiter, the god of diurnal (daylight) thunder. His precise nature was unclear even to Ovid.
The temple of Summanus was dedicated during the Pyrrhic War c. 278 BCE on June 20. It stood at the west of the Circus Maximus, perhaps on the slope of the Aventine. It seems the temple had been dedicated because the statue of the god which stood on the roof of the temple of Iupiter Capitolinus had been struck by a lightningbolt. Every June 20, the day before the summer solstice, round cakes called summanalia, made of flour, milk and honey and shaped as wheels, were offered to him as a token of propitiation: the wheel might be a solar symbol.
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