The Archer

Abbreviation: Sgr
Genitive: Sagittarii

The constellation of Sagittarius

Sagittarius is a member of the zodiac. This is one of the most ancient of constellations, harking back to Babylonia where it represented the god Nerigal or Nergal, a centaur-like creature with a bow and arrow. The Greeks also associated this constellation with a centaur armed with a bow. It may represent Chiron, esteemed tutor to many a Greek hero. The southern hemisphere also has a centaur constellation.

The asterism of the 'Teapot' is composed of the stars λ Sgr, φ Sgr, σ Sgr, τ Sgr, ζ Sgr, ε Sgr, γ Sgr and δ Sgr.

Notable Features

Designation Name Description
α Sgr Rukbat
β1 Sgr Arkab Prior
β2 Sgr Arkab Posterior
γ Sgr Alnasl This star lies in the direction of the galactic centre.
δ Sgr Kaus Media
ζ Sgr Ascella
κ Sgr Kaus Australis
λ Sgr Kaus Borealis
σ Sgr Nunki
V1216 Sgr This variable star is less than 10 light years away but is still too dim to be seen with the naked eye. It is found not far from the star ν1 Sgr on the sky map.
M8 Lagoon Nebula This giant emission nebula is one of the few faintly visible to the naked eye. Optical aids reveal more detail, including a star cluster.
M17 Horseshoe Nebula, Ω Nebula, Swan Nebula Binoculars or a telescope are necessary to see this star-forming region, one of the most massive ones so far discovered in our galaxy.
M18 This open star cluster sits in the rich star fields of Sagittarius. Binoculars are required to view it.
M20 Triffid Nebula A small telescope shows this object to be an unusual combination of open star cluster, emission nebula, reflection nebula and dark nebula.
M21 Even small binoculars will reveal this young open star cluster.
M22 One of the first globular cluster discovered, it is actually one of the brightest such objects in the sky. It is one of the very few globular clusters to possess a planetary nebula.
M23 A medium-size telescope will show this open star cluster lurking in the starfields of the Milky Way.
M24 The Milky Way runs right through this constellation; hence there are many fine clusters and nebula to be seen. M24 is such a star cluster and is sometimes called the Saggitarius Star Cloud. Binoculars can reveal up to 1000 stars.
M25 This is yet another open star cluster.
M28 This globular cluster contains a dozen or more millisecond pulsars. It is faintly visible in binoculars.
M54 Originally thought to belong to our galaxy, this globular cluster most likely belongs to a nearby galaxy called the Sagittarius Dwarf Elliptical Galaxy.
M55 This is another globular cluster visible through binoculars although to resolve it into individual stars, a medium-size telescope will be required.
M69 This metal-rich globular cluster lies near the galactic centre.
M70 This globular cluster lies near its neighbour, M69.
M75 A telescope will reveal this globular cluster with its densely concentrated core of old stars.
C57 Barnard's Galaxy Barnard's Galaxy is a barred irregular galaxy and a member of our own Local Group. It is detectable in a medium-size telescope.
Sgr A* Galactic Centre The galactic centre is denoted by the a bright radio source called Sagittarius A* (pronounced Sagittarius A Star). It is thought to be the location of the supermassive black hole at the very centre of our galaxy. It is located on the sky map not far from the star γ Sgr.