Astronomical symbols

Astronomical symbols are symbols used to represent astronomical objects, theoretical constructs and observational events in astronomy. The earliest forms of these symbols appear in Greek papyri of late antiquity. The Byzantine codices in which the Greek papyri were preserved continued and extended the inventory of astronomical symbols. New symbols were further invented to represent many just-discovered planets and minor planets discovered in the 18th-20th centuries.

All these symbols were once commonly used by professional astronomers, amateur astronomers, and astrologers. While they are still commonly used in almanacs and astrological publications, their occurrence in published research and texts on astronomy is relatively infrequent, with some exceptions such as the Sun and Earth symbols appearing in astronomical constants, and certain zodiacal signs used to represent the solstices and equinoxes.

Unicode has formally assigned codepoints to most symbols, mainly in Miscellaneous Symbols Block (2600-26FF) and Miscellaneous Symbols and Pictographs Block (1F300-1F5FF).

The use of astronomical symbols for the Sun and Moon dates to antiquity. The forms of the symbols that appear in the original papyri of Greek horoscopes are a circle with one ray () for the Sun and a crescent for the Moon. The modern sun symbol, a circle with a dot (☉), first appeared in Europe in the Renaissance.

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