Piscis Austrinus
What is Piscis Austrinus?
Constellations· Autumn evenings low south (N) · the lonely 1st-mag star. Home of Fomalhaut, the lone first-magnitude star of the autumn southern sky — the fish drinking the water poured by Aquarius. With no bright neighbours it is nicknamed "the solitary one". Look low in the south on autumn evenings in the Sky view.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Piscis Austrinus is in your sky right now: https://nowsky.org/solar/sky?sel=con:Piscis Austrinus — location and time set automatically, no login.
Stars of the figure
| Star | Magnitude |
|---|---|
| Fomalhaut | 1.2 |
The 1 brightest of the 6 stars used in the figure (6 lines). Lower magnitude means brighter.
Constellation basics
| Season | autumn evenings, low in the south (N) |
|---|---|
| Brightest star | Fomalhaut (α, 1.2) |
| How to find | the lone bright star below the Great Square |
| Area rank | 88 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- When can I see Piscis Austrinus?
- autumn evenings, low in the south (N).
- How do I find Piscis Austrinus?
- the lone bright star below the Great Square.
- What is the brightest star in Piscis Austrinus?
- Fomalhaut, magnitude 1.2.
- Where is Piscis Austrinus in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
Fomalhaut is three — a family spread 8° across the sky
Fomalhaut looks like a solitary star, but it is a system of three. The orange dwarf Fomalhaut B, 2° away, has long been known as a companion sharing its motion, and in 2013 a red dwarf fully 5.7° away in Aquarius was confirmed as the third member, Fomalhaut C. The three span 8° of sky and about 2.5 light-years of real space, loosely bound.
A system this wide is held together only barely by gravity and could be scattered by a passing star. Both A and C carry dust disks of their own, prompting the interpretation that the widely separated companions disturb each other's disks. The lonely star of the Southern Fish is in fact a system with relatives reaching into another constellation, relatives that simply cannot be seen by eye.
The constellation in depth
Piscis Austrinus is one of Ptolemy's 48 constellations and is actually older than the zodiacal Pisces. The Babylonians already drew a fish here, and in Greek myth it is the great fish that rescued the Syrian goddess Derceto when she threw herself into a lake. It is pictured drinking the stream poured out by Aquarius.
The star of the show is Fomalhaut, an A-type star 25 light-years away. In 2008 Hubble imaged a planet candidate inside its dust disk, and JWST later resolved three nested dust belts around it. The name means "mouth of the fish" in Arabic, and it sits exactly at the fish's mouth.
On September to November evenings, drop straight down from the Great Square of Pegasus toward the southern horizon and you meet a single bright star: Fomalhaut. The rest of the fish is 3rd–4th magnitude and needs a dark sky. From Seoul it climbs only about 20 degrees, so find a clear southern horizon — or check it in the Sky view.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.