The Constellation Circinus
by Dominic Ford
The constellation Circinus.
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Source: Stellarium.
Source: Stellarium.
Circinus is the fourth smallest constellation, squeezed into a narrow gap between the front feet of Centaurus and Triangulum Australe.
It represents a pair of compasses and together with its neighbor Norma – a set square – forms a pair of constellations which celebrate drawing instruments. Both were introduced by the French astronomer Nicolas Louis de Lacaille in 1756.
Circinus is visible in the far southern sky in the months around April, but contains only one star brighter than fourth magnitude. It lies across the plane of the Milky Way and despite its small size contains four open clusters with NGC numbers, including the Caldwell object C88 (NGC 5823).
Date First Appeared
1756 (Lacaille)
1756 (Lacaille)
Sky Area
0.2% of the sky
93.4 square degrees
0.2% of the sky
93.4 square degrees
Messier Objects
Circinus contains no Messier objects
Circinus contains no Messier objects
| Stars | Open Clusters | Globular Clusters | Galaxies |
| Stars | Open Clusters | Globular Clusters | Galaxies |
| α-Cir (mag 3.2) | NGC 5823 (mag 7.9) | ||
| β-Cir (mag 4.1) | NGC 5715 (mag 9.8) | ||
| γ-Cir (mag 4.5) | NGC 5288 (mag 11.8) | ||
| ε-Cir (mag 4.9) | NGC 5359 | ||
| θ-Cir (mag 5.0) | |||
| δ-Cir (mag 5.1) | |||
| η-Cir (mag 5.2) | |||
| HD 131342 (mag 5.2) | |||
| HD 129422 (mag 5.4) | |||
| HD 135591 (mag 5.4) | |||
| HD 125835 (mag 5.6) | |||
| HD 136359 (mag 5.7) | |||
| HD 120913 (mag 5.7) | |||
| HD 124471 (mag 5.7) | |||
| HD 120404 (mag 5.8) | |||
| HD 135160 (mag 5.8) | |||
| HD 126241 (mag 5.8) | |||
| HD 129954 (mag 5.9) | |||
| HD 126862 (mag 5.9) | |||
| AX Cir (mag 6.0) | |||
| HD 121932 (mag 6.0) | |||
| HD 128020 (mag 6.0) | |||
| ζ-Cir (mag 6.1) | |||
| HD 123377 (mag 6.1) | |||
| HD 123492 (mag 6.1) |