What it looks like
Circinus is a small southern constellation introduced by Lacaille in 1756, drawn as a pair of dividers or compasses used for measuring on maps. It lies in the rich Milky Way region beside Alpha Centauri and the Southern Cross, and contains the Circinus Galaxy — one of the nearest active galaxies to the Milky Way.
Brightest stars
Circinus has no bright stars; its brightest, Alpha Circini, sits near magnitude 3.2.
| Star | Magnitude | Distance | Meaning |
|---|---|---|---|
| Alpha Circini | +3.19 | 54 ly | — |
| Beta Circini | +4.07 | 100 ly | — |
| Gamma Circini | +4.48 | 510 ly | — |
| Delta Circini | +5.04 | 670 ly | — |
Mythology and history
Circinus has no ancient mythology. It was created by Lacaille in 1756 and named after the draughtsman's compasses, one of his group of constellations celebrating tools of science and craft.
The draughtsman's compasses
Circinus was introduced by Lacaille in 1756 as 'Circinus' — the pair of compasses used by mapmakers and astronomers. It belongs to the same scientific family as Norma (the set square), Telescopium, Microscopium and Caelum. Placed in the rich Milky Way region beside Alpha Centauri and the Southern Cross, Circinus is faint in its own right but occupies one of the most crowded and interesting parts of the southern sky.
How to find it
Look just south of Alpha Centauri on autumn and winter evenings from the southern hemisphere.
- Find Alpha Centauri first; Circinus lies just south of it.
- Small and faint — use a star chart or planetarium app.
- Best from the southern hemisphere on autumn and winter evenings.
Key facts
- Abbreviation
- Cir
- Genitive
- Circini
- Meaning
- The Compasses
- Brightest star
- Alpha Circini
- Main stars
- 3
- Area rank
- 85th
- Best visible
- June
- Declination
- -60°
- Meteor showers
- —
- Neighbours
- Centaurus, Musca, Apus, Triangulum Australe, Norma, Lupus
Deep-sky objects
The Circinus Galaxy is one of the closest active galaxies to the Milky Way, about 13 million light-years away, though it is heavily obscured by dust in the galactic plane. The constellation also contains the open cluster NGC 5823 and the faint planetary nebula NGC 5315.
Frequently asked questions
What does the constellation Circinus look like?
Circinus is a faint southern constellation named for the draughtsman's compasses, lying beside bright Alpha Centauri and home to the Circinus Galaxy.
What is the brightest star in Circinus?
The brightest star in Circinus is Alpha Circini, shining at around magnitude 3.19.
When is Circinus best visible?
Circinus is best seen from southern hemisphere during June.
What is the story behind Circinus?
Circinus has no ancient mythology. It was created by Lacaille in 1756 and named after the draughtsman's compasses, one of his group of constellations celebrating tools of science and craft.
Which constellations are near Circinus?
Circinus borders Centaurus, Musca, Apus, Triangulum Australe, Norma and Lupus.
Centaurus
Musca