Chapter Ⅳ

Birds, Music & the Summer Sky

Summer's Milky Way is an aviary: a swan gliding down the stream, an eagle rising against it, a lyre whose music once unlocked the underworld — and a helpful dolphin.

Cygnus & Lyra — the Swan and the Lyre

Two myths sharing one river of stars.

Cygnus: either Zeus disguised as a swan (the seduction of Leda, mother of Helen of Troy), or — more touching — the youth Cycnus, who dove again and again into the river Eridanus to gather the charred bones of his friend Phaethon after the boy crashed the Sun's chariot. The gods, moved, made him the swan that forever glides down the celestial river.

Lyra is the lyre of Orpheus, whose music made stones weep and persuaded Hades to release his wife Eurydice — lost again by a single backward glance. After Orpheus's death the Muses set his lyre among the stars, with brilliant blue-white Vega as its handle.

In the sky: Cygnus's tail-star Deneb + Vega + Aquila's Altair = the Summer Triangle. Deneb looks the faintest of the three but is by far the mightiest: ~2,600 light-years away, one of the most luminous stars known.

Aquila & Delphinus — the Eagle and the Dolphin

Zeus's thunder-bird, and the sea's best matchmaker.

Aquila is the eagle that carried Zeus's thunderbolts — and carried the shepherd boy Ganymede up to Olympus to be cup-bearer of the gods (Ganymede himself pours just south of here as Aquarius). The tiny arrow beside the eagle, Sagitta, is variously Heracles' arrow or Cupid's.

Delphinus: when the nymph Amphitrite fled Poseidon's marriage proposal, a dolphin found her, pleaded the sea-god's case, and returned with a bride. The grateful Poseidon gave the matchmaker a place in the sky — four faint stars that genuinely look like a dolphin arcing out of the water.

In the sky: Aquila's Altair is one of our nearest bright neighbours (17 light-years) and spins so fast — a rotation every ~9 hours — that it is visibly flattened at the poles.

Aquarius — the Cup-Bearer

Ganymede, pouring for the gods forever.

The most beautiful of mortals, taken by the eagle to serve nectar on Olympus. The chart draws him tipping his jar into a stream of faint stars that flows into the mouth of the Southern Fish, Piscis Austrinus.

This whole region was Babylon's “Sea” — a watery quarter of sky filled with the Fish, the Whale, the River and the Water-Snake, where the Sun swims during the rainy season.

In the sky: faint, but the stream ends at bright, lonely Fomalhaut — “the mouth of the fish” (Arabic fam al-ḥūt) — the solitary beacon of autumn's southern horizon.