The Dolphin among the stars: Amphitrite, Arion and a Sicilian riddle

Delphinus is a small constellation, but one of the most charming in the summer sky. Five close-set stars outline a diamond-shaped body and a curved tail, and anyone spotting it for the first time is struck by its likeness to a dolphin leaping out of the water. For the Greeks, a seafaring people, the dolphin was an animal friendly to humans and dear to the gods, and its presence among the stars is explained by more than one tale.

Poseidon's messenger

According to the version reported by Eratosthenes and Hyginus, Poseidon wished to marry the Nereid Amphitrite, but she, wanting to remain a virgin, fled and hid with Atlas, at the western edge of the world. The god sent many messengers to look for her. It was a dolphin that found her and persuaded her, with gentle words, to accept the marriage; Amphitrite thus became queen of the sea.

To reward the service, Poseidon placed the dolphin's image among the constellations. This link explains why in ancient art Amphitrite and Poseidon are often shown on chariots drawn by dolphins or surrounded by them. The dolphin thus became the emblem of mediation, able to bring two distant worlds together through persuasion rather than force.

Arion and the pirates

Another famous tale is that of Arion of Methymna, the lyre-singer from the island of Lesbos. Herodotus, in the first book of the Histories, relates that Arion, having amassed wealth in Italy and Sicily, set sail from Taras to return to Corinth, to the court of the tyrant Periander. On the open sea the sailors decided to kill him and rob him. Arion asked to sing one last time and then threw himself into the water.

A dolphin, drawn by the music, took him on its back and carried him to safety at Cape Taenarum, in the Peloponnese. When the sailors reached Corinth, Periander exposed them. According to later tradition the dolphin was placed in the sky in memory of the rescue. Yet another myth, told in the Homeric Hymn to Dionysus, speaks of Tyrrhenian pirates turned into dolphins by the god, and so destined to become friends of sailors.

Sualocin and Rotanev

The two brightest stars of Delphinus bear curious names, Sualocin and Rotanev, which derive neither from Greek nor from Arabic. They appeared in the star catalogue of the Palermo observatory published in 1814 by Giuseppe Piazzi. For many years no one understood their origin, until it was noticed that, read backwards, they form “Nicolaus Venator”, the Latinised form of the name of Niccolò Cacciatore, Piazzi's assistant and later his successor.

That astronomer's joke, hidden in a scientific catalogue, has survived and is now officially recognised. It is a reminder that star names are not only an ancient inheritance: even in modern times the sky has kept receiving stories, sometimes with a smile. Piazzi, after all, was already famous for having discovered at Palermo, on the night of 1 January 1801, the asteroid Ceres.

Delphinus therefore carries among the stars the memory of a special relationship between humans and the sea. It is the mediator who persuades a goddess, the rescuer who listens to music, the companion of sailors. In ancient symbolism and later in Christian imagery, where it often appears in mosaics and on oil lamps, the dolphin was associated with salvation and safe passage through the waters.