Crux, the Southern Cross

Crux, the Southern Cross, is the smallest of all 88 constellations, and one of the most famous. Its four bright stars make a compact cross, with two brilliant Pointers beside it.

Where is it from where I am?

How to spot it: Four bright stars in a small cross, with the two Pointers beside it. Source (opens in a new tab)

Smallest of the 88

Crux is the smallest constellation (opens in a new tab). Its brightest star, Acrux, is the most southerly first-magnitude star. The two bright stars beside it, Alpha and Beta Centauri, are the Pointers, and belong to the neighbouring Centaurus.

Lost and found

Ptolemy catalogued these stars, but as the hind legs of the centaur (opens in a new tab). The slow wobble of Earth's axis then carried them below the horizon of the Mediterranean world, and Europeans rediscovered them as sailors went south in the 15th and 16th centuries. Andrea Corsali sketched the cross in 1516 and called it more beautiful than any other sign in the sky; by 1603 it was listed as a constellation of its own.

Not the False Cross

A second, larger and fainter cross (opens in a new tab) nearby, made of stars from Carina and Vela, is known as the False Cross. The real one is smaller, brighter, and has the Pointers beside it.

The Coalsack and the Jewel Box

Beside the cross, a dark cloud of dust blots out the Milky Way: the Coalsack, which Amerigo Vespucci described in 1502 (opens in a new tab). For the Kamilaroi and Euahlayi peoples it is the head of the Emu in the Sky. Next to Mimosa lies the Jewel Box (opens in a new tab), a cluster about 6,400 light-years away that John Herschel named for its contrasting blue and orange stars; it is just visible to the unaided eye.

Where on Earth, and when

The whole key pattern rises from anywhere south of about 27°N.

North of about 33°N, none of it rises.

South of about 33°S, the whole key pattern never sets.

Its middle climbs at least 20° high, the finder's threshold for a suggestion, from anywhere south of about 10°N.

It is highest in the evening sky, at about 9 p.m. local time, in mid-May, from either hemisphere, wherever it rises. With daylight saving time, that is nearer 10 p.m. on the clock.

Worked out by this site from the Bright Star Catalogue, for a flat, clear horizon. Hills, buildings, haze and city light all cut into this; the air also lifts objects near the horizon by about half a degree. For your own place and night, use the sky finder.