Science & history · Constellation guide
Sagittarius, the archer
Sagittarius is a centaur drawing a bow at the scorpion next door. Its brightest stars make the Teapot, and just beyond them lies the direction of the centre of our Galaxy.
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: Eight stars in the shape of a teapot, east of Scorpius's tail. Source (opens in a new tab)
What you are looking at
A centaur-archer of Sumerian origin, the 15th largest constellation, aiming at the scorpion.
Ridpath (opens in a new tab) describes Sagittarius as a centaur drawing a bow aimed at neighbouring Scorpius. The figure began with the Sumerians as PA.BIL.SAG, a winged centaur-archer, a god of war and hunting; the Greeks took it over without the wings, and without a settled story of who he was.
Its star names follow Ptolemy's descriptions: Kaus Media, Kaus Australis and Kaus Borealis (opens in a new tab) are the middle, southern and northern parts of the bow, from the Arabic al-qaus; Nunki, borrowed from a Babylonian name for their sacred city of Eridu, is reputed to be the oldest star name in use.
Its alpha star is not its brightest. Ptolemy misjudged (opens in a new tab) alpha and beta as second magnitude when they are fourth, and Bayer, too far north to check, followed him; alpha, Rukbat, is only the 15th brightest star in the constellation.
Sources for this section Ian Ridpath, Star Tales: Sagittarius (opens in a new tab)
The Teapot
Eight of its stars make a teapot, with the Milky Way rising from the spout.
The Teapot (opens in a new tab) is the shape of eight main stars: the handle is phi, sigma, tau and zeta, the lid's top is lambda, and delta, epsilon and gamma make the spout. The same stars, with mu, were first seen as the archer's bow and arrow. NASA (opens in a new tab) notes it is best seen under skies without much light pollution. The Teapot has its own guide.
Five of those stars also make a smaller ladle, the Milk Dipper (opens in a new tab), aptly placed in a rich part of the Milky Way.
Sources for this section Ian Ridpath, Star Tales: Sagittarius (opens in a new tab); Preston Dyches, What Are Asterisms?, NASA Science (2021, updated 2024) (opens in a new tab)
Toward the centre of the Galaxy
When you look at Sagittarius you are looking toward the heart of the Milky Way.
Sagittarius contains dense Milky Way star fields (opens in a new tab) that lie toward the centre of our Galaxy. The exact centre is believed to be marked by a radio source, Sagittarius A*, near the border with Ophiuchus, close to the point of the archer's arrow.
The Night Sky Network (opens in a new tab) notes that for Northern Hemisphere observers the most prominent part of the Milky Way rises in the south-east marked by Scorpius and Sagittarius, and that the Great Rift, a lane of dark dust, runs down from the Summer Triangle toward Sagittarius.
Keep in mind The Milky Way is faint. It needs (opens in a new tab) clear, dark skies, eyes given time to adapt, and a new or crescent Moon; from a city you will see the Teapot's stars but not the glow behind them.
Sources for this section Ian Ridpath, Star Tales: Sagittarius (opens in a new tab); Kat Troche (Astronomical Society of the Pacific), The Great Rift, NASA Night Sky Network (2025) (opens in a new tab)
How to find it
Low in the south from mid-northern latitudes, high overhead from the Southern Hemisphere.
By this site's calculation (opens in a new tab), Sagittarius's middle reaches only about 21° up in the south from 40°N but about 84° up in the north from 35°S; it is highest at about 9 p.m. local time in mid-August.
It follows the scorpion across the sky: the archer is aimed at neighbouring Scorpius (opens in a new tab), so find red Antares and the scorpion's curved tail, then look east for the Teapot. In NASA's photograph (opens in a new tab) the Teapot sits just to the left of Scorpius.
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: Sagittarius (opens in a new tab); Preston Dyches, What Are Asterisms?, NASA Science (2021, updated 2024) (opens in a new tab)
What you can actually see
Under a dark sky, a nebula and a globular cluster that binoculars show at once.
The Lagoon Nebula, M8 (opens in a new tab), about 5,200 light-years away, is a cloud where new stars are forming. At magnitude 6 it is faintly visible to the unaided eye in dark skies and easy in binoculars or a small telescope; NASA gives August as the best time to look.
Messier 22 (opens in a new tab), about 10,000 light-years away and one of the closest globular clusters, is magnitude 5.1, visible to the naked eye in ideal conditions. Like other globular clusters it is a dense ball of very old stars, typically 12 to 13 billion years old.
Sources for this section NASA Hubble, Messier 8 (the Lagoon Nebula) (opens in a new tab); NASA Hubble, Messier 22 (opens in a new tab)
The Ladle of the Book of Poetry
A Chinese poem's ‘Ladle’, long taken for the Big Dipper, is in Sagittarius.
An ode in the Chinese Book of Poetry complains that the Ladle “lades out no liquor” (opens in a new tab), and that the Sieve beside it cannot sift. James Legge's note to his 1879 translation identifies the Sieve as one of the 28 mansions, part of Sagittarius, and the Ladle as the constellation next to it, also part of Sagittarius.
Ridpath (opens in a new tab) names the same pair as the seventh and eighth Chinese lunar mansions, Ji, the winnowing basket, and Dou, the dipper or Southern Dipper, made of the stars that now form the Milk Dipper, with mu.
Sources for this section The Shih King (Book of Poetry), Minor Odes, Fifth Decade, Ode 9 (Ta Tung), tr. James Legge (Sacred Books of the East vol. 3, 1879), Project Gutenberg #9394 (opens in a new tab); Ian Ridpath, Star Tales: Sagittarius (opens in a new tab)
Where on Earth, and when
The whole key pattern rises from anywhere south of about 56°N.
North of about 65°N, none of it rises.
South of about 65°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 41°N.
It is highest in the evening sky, at about 9 p.m. local time, in mid-August, 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: Sagittarius (opens in a new tab) for the figure, its star names, the Teapot, the Milk Dipper, the Galaxy's centre and the Chinese mansions · checked 2 October 2026
- Astronomy Preston Dyches, What Are Asterisms?, NASA Science (2021, updated 2024) (opens in a new tab) for the Teapot and light pollution · checked 27 September 2026
- Astronomy Kat Troche (Astronomical Society of the Pacific), The Great Rift, NASA Night Sky Network (2025) (opens in a new tab) for the Milky Way and the Great Rift · checked 27 September 2026
- Astronomy NASA Hubble, Messier 8 (the Lagoon Nebula) (opens in a new tab) for the Lagoon Nebula · checked 2 October 2026
- Astronomy NASA Hubble, Messier 22 (opens in a new tab) for Messier 22 · checked 2 October 2026
- History The Shih King (Book of Poetry), Minor Odes, Fifth Decade, Ode 9 (Ta Tung), tr. James Legge (Sacred Books of the East vol. 3, 1879), Project Gutenberg #9394 (opens in a new tab) for the Ladle and the Sieve, with Legge's note · checked 2 October 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 its height from 40°N and 35°S, and best month
