Sagittarius

Sgr · genitive Sagittarii · southern sky

The Sagittarius figure as the IAU defines it, drawn looking south with east to the left — the orientation you see standing outside.

At a glance

Catalogued stars
195
Visible to the eye
195 stars
Brightest star
Kaus Australis (1.79)
Best seen
July
Declination span
-44.5° to -16.0°
Nearest star
HD 191408 · 19.6 ly

Visible from everywhere south of about 46°N.

When and where to look for Sagittarius

Sagittarius crosses the meridian — its highest point in the sky — at local midnight around July, which makes the months from June to August the easiest time to find it in the evening. It spans declinations -44.5° to -16.0°, so visible from everywhere south of about 46°N.

The quickest way to find it is to open the live AR sky map and point your phone at the sky — if Sagittarius is above your horizon right now, its figure is drawn in the position it genuinely occupies above you.

Brightest stars in Sagittarius

StarMagTypeDistance
Kaus Australis20Eps Sgr1.79B9.5III143.3 ly
Nunki34Sig Sgr2.05B2.5V227.8 ly
Ascella38Zet Sgr2.60A3IV88.2 ly
Kaus Media19Del Sgr2.72K3III347.7 ly
Kaus Borealis22Lam Sgr2.82K1IIIb78.2 ly
Albaldah41Pi Sgr2.88F2II/III509.6 ly

Magnitude runs backwards: lower numbers are brighter, and anything below about 6.5 is beyond the naked eye under a dark sky.

What Sagittarius is made of

The catalogue lists 195 stars within Sagittarius, of which 195 are magnitude 6.5 or brighter — the limit of what an unaided eye picks up under a genuinely dark sky. The rest need binoculars or a telescope.

Spectral make-up

O2
B42
A34
F23
G14
K72
M8

Spectral class is a temperature ordering, running from O at around 30,000 K down to M below 3,500 K. A constellation is a direction, not a group, so this is simply what happens to lie along that line of sight.

The closest catalogued star in this direction is HD 191408 at 19.6 light years. The most distant is 6 Sgr at roughly 2,630 light years — stars that appear side by side here are nothing of the sort.

Deep-sky objects in Sagittarius

  • Lagoon Nebula — nebula
  • Sagittarius Star Cloud — star cloud
  • Sagittarius Cluster — globular cluster

These are marked on the sky map, so you can see where they sit relative to the constellation figure in real time.

Nearby constellations