Circinus

Cir · genitive Circini · southern sky

The Circinus 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
40
Visible to the eye
40 stars
Brightest star
Alp Cir (3.18)
Best seen
April
Declination span
-65.0° to -58.8°
Nearest star
Alp Cir · 54 ly

Visible from everywhere south of about 25°N.

When and where to look for Circinus

Circinus crosses the meridian — its highest point in the sky — at local midnight around April, which makes the months from March to May the easiest time to find it in the evening. It spans declinations -65.0° to -58.8°, so visible from everywhere south of about 25°N.

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

Brightest stars in Circinus

StarMagTypeDistance
Alp Cir3.18F1Vp54 ly
Bet Cir4.07A3V99.7 ly
Gam Cir4.48B5III + F8448.6 ly
Eps Cir4.85K2.5III407.7 ly
Del Cir5.04O8.5V—
The Cir5.08B4Vnp1,510 ly

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

What Circinus is made of

The catalogue lists 40 stars within Circinus, of which 40 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
B12
A6
F7
G2
K11

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 Alp Cir at 54 light years. The most distant is HD 125835 at roughly 2,026 light years — stars that appear side by side here are nothing of the sort.

Nearby constellations