Triangulum

Tri star chart (IAU and Sky & Telescope magazine, Roger Sinnott & Rick Fienberg).

One of the 88 IAU constellations.

Etymology and History

The triangle constellation is ancient Greek. It did not exist in Mesopotamia; the stars probably belonged to the Babylonian constellation of the Hired Man, ^{mul LU₂}ḪUN.GA (Aries). Although it was consistently present as a separate constellation in Greece, the authors disagree about its meaning. Aratos calls it ‘the sign’, the mathematical astronomers call it ‘triangle’. Accordingly, Eratosthenes reflects that some understand it as the initial letter of the word ‘Dios’, i.e. as the Greek capital letter Δ (Delta). Dios is the genitive of the name of Zeus. The astronomer reports that when Hermes arranged the constellations in the sky, he inserted ‘of Zeus’ as a possessive inscription - i.e. ‘constellations of Zeus’, the highest god.

Alternatively, Eratosthenes, the librarian of Alexandria and teacher of the princes of Egypt, reported that the constellation was the Nile Delta. He says that the Nile created a triangular outline of Egypt. The constellation therefore symbolises the land that is shaped by the Nile.

References

• References (general)
• References (Babylonian)
• References (ancient Greco-Roman)
• References (medieval)