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Corvus, the Crow, is a small, tight quadrilateral of four modestly bright stars sitting by itself in an otherwise empty stretch of spring sky, just southwest of Spica. There is nothing else nearby to compete with it, which is part of why its neat, boxy shape — sometimes called a sail — is so easy to pick out once you know where to look. It is one of Ptolemy's original 48 constellations. From Columbus, Ohio (about 40°N), it is a genuinely southern target: it never climbs very high, so it needs a clear, unobstructed view toward the south.
Finding it
The classic route is the same one that leads to Boötes and beyond: "arc to Arcturus, then drive a spike to Spica." Follow the curve of the Big Dipper's handle out to Arcturus, then continue in the same straight line — the "spike" — down to bright, blue-white Spica in Virgo. Corvus sits just to the southwest of Spica, its four stars forming a small, tidy box; some versions of the mnemonic extend a step further, "and on to Corvus," treating the crow as a natural third stop on the same line.
At Columbus's latitude, Corvus climbs only about 25–35° above the southern horizon at its highest — low enough that trees, buildings, or haze near the horizon can hide it entirely. It is not circumpolar; it is invisible for a large part of the year. Best viewing is April into May, with June evenings still workable before it sinks into evening twilight.
The stars
RA and Dec are J2000, matching the site's own sky chart, given exactly as supplied.
| Star | Designation | RA (h) | Dec (°) | Mag | Distance | Spectral type | Name |
|---|---|---|---|---|---|---|---|
| Gienah | γ Crv | 12.263 | −17.54 | 2.59 | 165 ly | B8 III giant | Arabic al-janāħ al-ghirāb al-yaman, "the right wing of the crow" |
| Kraz | β Crv | 12.573 | −23.40 | 2.65 | 140 ly | G-type giant | origin uncertain; no reliably sourced meaning |
| Algorab | δ Crv | 12.498 | −16.52 | 2.94 | 87 ly | A0, with a fainter companion | Arabic al-ghurāb, simply "the crow" |
| Minkar | ε Crv | 12.168 | −22.62 | 3.02 | ~303 ly | K2 III | Arabic, "the nostril (beak) of the crow" |
| Alchiba | α Crv | 12.140 | −24.73 | 4.02 | ~48 ly | F0 dwarf | Arabic al-khibā', "the tent." Despite carrying the "Alpha" designation, it is the faintest of the four main stars — a reminder that Bayer's Greek-letter ordering does not always track brightness. |
Myth and history
The fable that put Corvus in the sky also explains why two of its neighbors, Crater the Cup and Hydra the Water Snake, sit exactly where they do — all three constellations exist because of one story. As Hyginus records it in the Poetic Astronomy (2nd century CE), Apollo sent the crow to fetch water from a spring in a cup. The crow lingered by a fig tree, waiting for the fruit to ripen, and arrived late; to cover the delay, it snatched up a water snake and claimed the snake had blocked the spring. Apollo saw through the lie and punished it three ways at once: the crow's feathers turned black, its once-sweet voice became the harsh caw it has today, and it was set in the sky beside the cup — with the water snake stretched out permanently between them, close enough that the crow can see the water and can never reach it.
Non-Greek traditions read the same stars through very different frameworks. In Chinese astronomy, Corvus's main stars form Zhěn (軫, "Chariot"), the 28th and final of the 28 lunar mansions, closing the full circuit of that system within the Vermilion Bird of the South (南方朱雀) — the same way Corvus, at the far edge of Virgo, marks one boundary of the classical Greek zodiac's spring stretch. To Torres Strait Islanders, Corvus forms part of Tagai, a vast constellation depicting a man fishing: Tagai holds a spear in one hand (marked by the Southern Cross) and, in the other, a bunch of fruit called eugina — marked by the stars of Corvus. Arabic astronomers, working independently, named the individual stars for parts of the bird itself — wing, beak, tent — rather than retelling the fable.
Deep sky
The Antennae Galaxies (NGC 4038/4039) sit near the Corvus–Crater border, roughly 45 million light-years away — a pair of spiral galaxies caught mid-collision, their disks torn into two long, thin tidal tails of stars that give the pair its name. The two galaxies passed through each other for the first time an estimated 600 million years ago and are expected to finish merging into a single elliptical galaxy tens to hundreds of millions of years from now. Visually, through an amateur telescope, it is a faint smudge around 10th magnitude that needs a mid-size scope and a dark sky to register at all — the tidal "antennae" themselves show up only in long-exposure imaging, not at the eyepiece. Because the collision is close and well studied, the Antennae are one of the standard nearby laboratories for understanding galaxy mergers in general, including the one the Milky Way and Andromeda are expected to undergo several billion years from now.
Key dates
| Date | Event |
|---|---|
| c. 275 BCE | Aratus's Phaenomena places the crow pecking at the water snake beside the bowl. |
| c. 150 CE | Ptolemy catalogues Corvus among the Almagest's 48 constellations, alongside Crater and Hydra. |
| 1785 | William Herschel catalogues NGC 4038 and NGC 4039, not yet understood as a colliding pair. |
| 1972 | Alar and Juri Toomre's computer models of tidal tails, using the Antennae as a test case, show that gravity alone can produce this shape from two colliding disk galaxies. |