Fornax
What is Fornax?
Constellations· Autumn–winter evenings · inside a bend of Eridanus. Fornax is Lacaille's tribute to the chemist's furnace. Its stars are faint, but the Fornax galaxy cluster and the Hubble Ultra Deep Field lie in this direction, making it a window onto the distant universe.
📍 Visible from where you are right now — computed in your browser
Stars of the figure
| Star | Magnitude |
|---|---|
| Dalim | 3.9 |
| Beta Fornacis | 4.5 |
The 2 brightest of the 2 stars used in the figure (1 lines). Lower magnitude means brighter.
Deep-sky objects near this constellation
Constellation basics
| Season | Nov–Dec evenings, low in the south; visible from New York and, very low, from London |
|---|---|
| Brightest star | α Fornacis (Dalim), mag 3.9 |
| How to find | south of Cetus, inside the curve of Eridanus |
| Area rank | 41st of 88 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
The Fornax Dwarf and its six globular clusters
In 1938 the American astronomer Harlow Shapley found a small galaxy orbiting the Milky Way, about 460,000 light-years away in the direction of Fornax. It is called the Fornax Dwarf galaxy. Its stars are thinly spread, so it is very faint. Even though it is a nearby galaxy, it is barely visible to the naked eye or a small telescope.
This little galaxy has six globular clusters, which are balls of hundreds of thousands of old stars packed together. Few of the small galaxies around the Milky Way have so many. How such a small galaxy made these clusters and has held on to them is an important question for scientists who study how galaxies form.
It is also notable that the clusters are spread out instead of having sunk to the galaxy's centre. Astronomers study this as a clue to how invisible dark matter is spread through the galaxy. In the same direction as the Hubble Ultra Deep Field, which revealed the distant universe, lies a nearby example for studying galaxies too.
The constellation in depth
Fornax was drawn by Lacaille in the 1750s, and its first name was the Chemical Furnace, a tool chemists of the time used to heat substances in experiments. The constellation sits inside a great bend in the stars of Eridanus, the river. With no bright star of its own, it looks like a clearing surrounded by water.
Its stars are faint, but it has many galaxies. The Fornax galaxy cluster, about 62 million light-years away, holds beautiful galaxies such as the barred spiral NGC 1365. On the cluster's edge, NGC 1316, also called Fornax A, is one of the brightest radio sources in the sky. Its tangled dust lanes are the remains of smaller galaxies it swallowed.
In 2004 the Hubble Space Telescope stared for a long time at a tiny patch inside Fornax. The resulting Hubble Ultra Deep Field image captured galaxies from about 13 billion years ago. Light from distant galaxies set out long ago, so this picture shows the universe when it was very young.
Fornax can be seen from mid-northern latitudes, low in the south on November and December evenings. Look south of Cetus, inside the curve of the stars of Eridanus. Its brightest star, Alpha Fornacis or Dalim, is only magnitude 3.9, so a dark site helps. In the Sky view, set New York on a November night and look south, or choose a southern city to see it high overhead.
Frequently asked
- When can I see Fornax?
- Fornax is best seen in Nov–Dec evenings, low in the south; visible from New York and, very low, from London.
- How do I find Fornax?
- To find Fornax, look for south of Cetus, inside the curve of Eridanus.
- What is the brightest star in Fornax?
- The brightest star in Fornax is Dalim, at magnitude 3.9.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.