Ara
What is Ara?
Constellations· Southern winter · just south of the Scorpion's tail. An ancient constellation said to be the altar on which the gods swore their oath before the war with the Titans. Tucked into the Milky Way just south of the Scorpion's tail, it is rich in clusters but sits almost on the horizon from Korea.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Ara is in your sky right now: https://nowsky.org/solar/sky?sel=con:Ara — location and time set automatically, no login.
Stars of the figure
| Star | Magnitude |
|---|---|
| Alpha Arae | 2.8 |
| Beta Arae | 2.8 |
The 2 brightest of the 4 stars used in the figure (3 lines). Lower magnitude means brighter.
Deep-sky objects near this constellation
Constellation basics
| Season | Jun–Aug evenings; barely above the horizon from Korea |
|---|---|
| Brightest star | β Arae, mag 2.8 |
| How to find | directly below Shaula, the Scorpion's sting |
| Area rank | 63rd of 88 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- When can I see Ara?
- Jun–Aug evenings; barely above the horizon from Korea.
- How do I find Ara?
- directly below Shaula, the Scorpion's sting.
- What is the brightest star in Ara?
- Alpha Arae, magnitude 2.8.
- Where is Ara in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
Westerlund 1 — the cluster of the galaxy's heaviest stars
Twelve thousand light-years away in the direction of Ara lies Westerlund 1, the most massive young cluster in the Milky Way. Bengt Westerlund found it in 1961, but hidden by dust it drew little attention until infrared observations in the 2000s revealed dozens of supergiants, Wolf–Rayet stars and hypergiants within tens of thousands of solar masses. At about five million years old, the cluster has entered the age when its stars begin to explode.
A magnetar was found in the cluster in 2005, evidence that even a star of more than forty solar masses can leave a neutron star rather than a black hole — meaning such a star must shed much of its mass before it dies. Deep in the southern Milky Way, this cluster is a specimen showing in one place how the ends of stars diverge, and Webb turned to it in 2023.
The constellation in depth
Ara, the Altar, is one of Ptolemy's 48 constellations, said to be the altar where the Olympian gods gathered to swear their oath before the war against the Titans. Old star maps drew smoke rising from it and merging with the Milky Way. Finding it is simple: it lies directly south of the Scorpion's tail.
Because it sits in the heart of the Milky Way it is full of clusters. NGC 6397 is one of the nearest globular clusters to us at about 7,800 light-years, and mu Arae is a Sun-like star with four known planets, often cited in exoplanet work. Beta Arae, the brightest star, is a supergiant some 140 times the Sun's diameter.
At declinations of −50° to −65° it is effectively invisible from Korea; only from the far south does its top graze the horizon around midnight in July. From the southern hemisphere it passes near the zenith on winter evenings. In the Sky view choose Sydney or Cape Town on a July evening and look below the Scorpion's sting.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.