Sagittarius Constellation

Sagittarius the Archer aims his bow directly at the heart of the Milky Way, and it shows: this constellation sits in the densest, most star-rich direction of our entire galaxy, glowing with nebulae, star clusters, and the swirling light of billions of unresolved stars. Usually depicted as a centaur — half man, half horse — drawing back an arrow, Sagittarius is most easily recognized today by its Teapot asterism, a simple, friendly shape that makes this mythologically rich region surprisingly easy to find.

Sagittarius at a Glance

• AbbreviationSgr
• Genitive FormSagittarii
• MeaningThe Archer
• Constellation FamilyZodiac
• Area867 sq. degrees (15th largest of 88)
• Right Ascension17h 42m – 20h 26m
• Declination-11.5° to -45.5°
• Brightest StarKaus Australis (magnitude 1.79)
• Best Evening ViewingAugust, visible 55°N to 90°S
• Sun's Actual TransitDecember 17 – January 20 (astrology: November 22 – December 21)

Mythology and History

Sagittarius is traditionally depicted as a centaur, and while several origin stories exist, many trace the constellation back to Crotus, a satyr-like figure raised by the Muses and credited with inventing the art of archery on horseback; as a reward for his skill and companionship, the Muses asked Zeus to place him among the stars. A separate but persistent tradition instead identifies the archer with Chiron, the wise and gentle centaur who tutored Hercules and other Greek heroes — though Chiron is more commonly associated with the neighboring, fainter constellation Centaurus. Sagittarius was one of the 48 constellations recorded by Ptolemy in the 2nd century AD, and its position directly in front of the galactic center made it one of the most important regions of sky to ancient skywatchers, long before anyone understood what lay behind it.

Notable Stars in Sagittarius

Kaus Australis, the brightest star in Sagittarius at magnitude 1.79, is a blue-white giant roughly 143 light-years away marking the southern tip of the archer's bow. Nunki, a hot blue-white star of magnitude 2.05, was historically one of the most important navigational stars for Pacific and Arab sailors, prized for its brightness and position near the Milky Way's densest reaches.

Deep-Sky Objects

Sagittarius contains more Messier objects than any other constellation — fifteen in total — because it looks straight down the most crowded arm of our own galaxy. The Lagoon Nebula (M8) is a vast, glowing nursery where new stars are actively forming, bright enough to see with the naked eye under dark skies. The Trifid Nebula (M20) and Omega Nebula (M17) add still more star-forming regions nearby, while numerous globular clusters, including M22, one of the brightest in the sky, orbit nearby in the galactic halo.

• Lagoon Nebula (M8) — a vast, glowing stellar nursery visible to the naked eye, where new stars are actively being born
• Trifid Nebula (M20) — a striking nebula divided into dark lanes of dust, giving it its three-lobed name
• Omega Nebula (M17) — also called the Swan Nebula, a bright star-forming region resembling a swan or checkmark through a telescope

Neighboring Constellations and How to Find It

Sagittarius is easiest to find by looking for the Teapot, a simple asterism of eight stars that genuinely resembles a teapot with a handle and spout, low in the southern sky during summer evenings. It reaches its highest point around August and is best viewed from southern latitudes, where the rich star clouds of the galactic center climb well clear of the horizon. Sagittarius borders Aquila, Scutum, Serpens Cauda, Ophiuchus, Scorpius, Corona Australis, Telescopium, Microscopium, Capricornus, and Indus.