COSMOS / CONSTELLATIONS / CIR
Circinus (Compasses)
The Compasses. IAU abbreviation Cir. One of the 14 southern constellations that Nicolas-Louis de Lacaille introduced after observing from the Cape of Good Hope in 1751–1752.
STAR CHART
KEY FACTS
- IAU abbreviation
- Cir
- Latin name / genitive
- Circinus / Circini
- Position
- Right ascension ≈ 14 h 47 m; declination −70° to −56°
- Visibility from Türkiye
- Not visible from Türkiye; it is observed from the southern hemisphere.
- Best time to observe
- From the southern hemisphere it is best placed around 21:00 in late June.
- Number of stars
- 40 stars brighter than magnitude 6.5 in the catalogue; 4 brighter than 5 and 1 brighter than 4.
INTERACTIVE LAB
Where is Circinus tonight?
This constellation cannot be seen from Türkiye, so the lab opens for Sydney. Drag the time slider through the southern night, use the “Best night” button to jump to the best date, and switch the city to Ankara to see why it never rises there.
MYTH, HISTORY AND OBSERVING
A small constellation that Lacaille dedicated in 1756 to the drawing compass; it lies right next to Alpha Centauri. The nearby active Circinus Galaxy hides behind the dust of the Milky Way. It is not visible from Türkiye.
BRIGHTEST STARS
| Star | Magnitude | Distance (light-years) | Spectral type |
|---|---|---|---|
| α Cir | 3.18 | 54 | F1Vp |
| β Cir | 4.07 | 100 | A3V |
| γ Cir | 4.48 | 449 | B5III |
| ε Cir | 4.85 | 408 | K2.5III |
| δ Cir | 5.04 | — | O8.5V |
| θ Cir | 5.08 | 1,510 | B4Vnp |
| η Cir | 5.16 | 276 | G8III |
| HIP 73036 | 5.18 | 161 | K1III |
Magnitude: apparent brightness; the smaller the number, the brighter the star. Distances derive from parallax measurements and are uncertain for distant stars. Source: HYG v4.1 star catalogue (CC BY-SA 4.0).
SOURCES
Position, visibility and best observing time were computed approximately for this page from the catalogue stars (Ankara, 39.9° N). The 88 constellations were adopted by the IAU in 1922; their boundaries were drawn by Eugène Delporte in 1930.