Apus
What is Apus?
Constellations· Southern winter · between the Southern Triangle and the pole. The bird of paradise, whose Latin name means 'footless' — 16th-century Europe knew the bird only from New Guinea skins prepared without feet. A few faint stars close to the south celestial pole.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Apus is in your sky right now: https://nowsky.org/solar/sky?sel=con:Apus — location and time set automatically, no login.
Stars of the figure
| Star | Magnitude |
|---|---|
| Alpha Apodis | 3.8 |
The 1 brightest of the 2 stars used in the figure (1 lines). Lower magnitude means brighter.
Constellation basics
| Season | circumpolar in the south, best Jun–Jul; never visible from Korea |
|---|---|
| Brightest star | α Apodis, mag 3.8 |
| How to find | south of Triangulum Australe, north of Octans |
| Area rank | 67th of 88 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- When can I see Apus?
- circumpolar in the south, best Jun–Jul; never visible from Korea.
- How do I find Apus?
- south of Triangulum Australe, north of Octans.
- What is the brightest star in Apus?
- Alpha Apodis, magnitude 3.8.
- Where is Apus in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
A cluster that may hide many black holes — NGC 6101 in Apus
Apus contains the globular cluster NGC 6101, 50,000 light-years away. It is an inconspicuous cluster, but in 2016 simulations by a team at the University of Surrey found that explaining why its centre is not concentrated like other globulars requires several hundred stellar black holes to have remained inside it. Until then black holes were thought to be ejected from clusters.
Black holes within a cluster can pair up and merge, emitting gravitational waves, and it is debated whether some of the black-hole mergers detected since 2015 came from such clusters. NGC 6101 was the first cluster singled out as a candidate. Inside the constellation of the footless bird near the south celestial pole, there may be a crowd of black holes that no one can see.
The constellation in depth
Apus is one of the twelve southern constellations created by the Dutch navigators in the 1590s. Its Latin name means 'without feet': Europe of the time knew the bird of paradise only from New Guinea skins prepared with the feet removed, and so believed the bird spent its whole life in the air. It appeared in Bayer's atlas of 1603.
Alpha Apodis, the brightest star at magnitude 3.8, is an orange giant about 450 light-years away. Delta Apodis is a wide double of two red giants, a good binocular pair for comparing colours. The constellation also contains NGC 6101 and IC 4499, two of the older globular clusters in the Milky Way. Both clusters need a telescope to resolve into stars.
At declinations of −67° to −83° it can never be seen from Korea, while in the southern hemisphere it never sets. On June and July evenings look below Triangulum Australe, short of the pole, for a handful of faint stars. In the Sky view, set Cape Town or Sydney on a July evening and zoom in low in the southern sky.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.