Science & history · Constellation guide
Centaurus, the centaur
Centaurus is a large southern constellation that wraps around the Southern Cross. It holds two of the sky's standouts: Alpha Centauri, the nearest star system, and Omega Centauri, the brightest globular cluster.
About this picture
NASA/Goddard Space Flight Center Scientific Visualization Studio. Gaia DR2: ESA/Gaia/DPAC. Constellation figures based on those developed for the IAU by Alan MacRobert of Sky and Telescope magazine (Roger Sinnott and Rick Fienberg). NASA's page (opens in a new tab).
The map is a composite of 1.7 billion catalogued stars, not a photograph from one place: it shows stars far too faint for the eye, and no weather, Moon or city light. It is drawn here in this chart's projection, with each star where it was in 2000; the fastest-moving bright star has shifted about a minute of arc since, far less than a pixel here.
How to spot it: Alpha and Beta Centauri, the two bright Pointers to the Southern Cross. Source (opens in a new tab)
The wise centaur
A large southern constellation showing Chiron, the one wise centaur.
The constellation is the centaur Chiron (opens in a new tab), wise and scholarly, unlike the wild centaurs of myth. It is the ninth largest of the 88, and in Ptolemy's day it included the stars that are now the Southern Cross.
Its brightest stars lead the eye elsewhere: Alpha Centauri is the nearest star system to the Sun, and Beta, Hadar, takes its name, Ridpath (opens in a new tab) says, from an Arabic word for one of a pair of stars.
Sources for this section Ian Ridpath, Star Tales: Centaurus (opens in a new tab)
The Pointers
Alpha and Beta Centauri, side by side, point to the Southern Cross.
Alpha and Beta Centauri act as pointers to Crux (opens in a new tab), the Southern Cross. Ptolemy described Beta as lying on the centaur's left knee.
By this site's calculation (opens in a new tab), the two Pointers are about 4° apart, and the line through them leads to the cross.
Sources for this section Ian Ridpath, Star Tales: Centaurus (opens in a new tab); Bright Star Catalogue, 5th Revised Ed. (Hoffleit & Warren 1991), as computed by this site's star engine (opens in a new tab)
Omega Centauri
A ‘star’ in Ptolemy's catalogue turned out to be the biggest globular cluster in our sky.
Ptolemy listed Omega Centauri as a single star nearly 2,000 years ago. NASA's Hubble team (opens in a new tab) traces how it was reclassified: Edmond Halley reported it as a nebula in 1677, and in the 1830s John Herschel was the first to recognise it as a globular cluster.
It is home to around 10 million stars (opens in a new tab), about 17,000 light-years away, and at magnitude 3.7 it is an easy naked-eye sight from the right place.
How to see it Omega Centauri is visible (opens in a new tab) only from low northern latitudes and south of the equator, best in southern autumn. To the eye it can pass for a slightly fuzzy star, which is how Ptolemy came to list it as one.
Sources for this section NASA Hubble, Caldwell 80 (Omega Centauri) (opens in a new tab)
How to find it
A southern constellation, wrapped around the Southern Cross.
By this site's calculation (opens in a new tab), the centaur's middle stands about 73° up in the south at its highest from 35°S but only about 18° up in the south from 20°N, and it is highest at about 9 p.m. local time in mid-June.
Find the cross and the two bright Pointers (opens in a new tab): the centaur's body and legs surround them.
Sources for this section Bright Star Catalogue, 5th Revised Ed. (Hoffleit & Warren 1991), as computed by this site's star engine (opens in a new tab); Ian Ridpath, Star Tales: Centaurus (opens in a new tab)
Where on Earth, and when
The whole key pattern rises from anywhere south of about 29°N.
North of about 53°N, none of it rises.
South of about 53°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 18°N.
It is highest in the evening sky, at about 9 p.m. local time, in mid-June, 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.
Sources
- History Ian Ridpath, Star Tales: Centaurus (opens in a new tab) for Chiron, its size, the Pointers and Hadar · checked 27 September 2026
- Astronomy NASA Hubble, Caldwell 80 (Omega Centauri) (opens in a new tab) for Omega Centauri · checked 27 September 2026
- Astronomy Bright Star Catalogue, 5th Revised Ed. (Hoffleit & Warren 1991), as computed by this site's star engine (opens in a new tab) for the Pointers' separation, its height and best month
