Mensa, the Table, is the faintest of all the constellations, a small patch near the south celestial pole named after Table Mountain above Cape Town.
At a glance
| stars in the figure | 2 |
|---|---|
| nearest star of the figure | Alpha Mensae, 33.3 light-years (10.2 pc) |
| farthest star of the figure | Beta Mensae, 794 light-years (243 pc) |
| depth | the farthest is 24 × farther than the nearest |
Read off the piece’s own catalogue, the same values it draws with.
About Mensa
Mensa was introduced by Nicolas-Louis de Lacaille, the French astronomer who mapped the southern sky from the Cape of Good Hope. He called it Mons Mensae, after Table Mountain, which looms over the city where he worked, and the name was later shortened. It has no bright star at all: even its leading star is barely visible to the eye under a dark sky.
What it lacks in stars it gains in neighbours. Part of the Large Magellanic Cloud spills across its border from Dorado, so a dim constellation shares its patch of sky with a whole satellite galaxy, much farther away than anything else in the figure. Alpha Mensae itself is a nearby yellow dwarf, a star not unlike the Sun, faint only because it is small and unremarkable.
Mensa lies so close to the south celestial pole that from much of the southern hemisphere it never sets. From the northern hemisphere it is never seen.
What you see in the piece
Its figure is a single line between two stars. Fly out with CONSTELLATIONS (N) on and leave the HUMAN EYE view (E): one end is a nearby Sun-like star, the other lies far behind it, and the line stretches into a long thread pointing away from Earth.
Questions
What is the faintest constellation?
Mensa, the Table, is the faintest constellation: none of its stars is bright, and its leading star is only just visible to the naked eye under a dark sky.
How far apart are the stars of Mensa?
The figure joins Alpha Mensae, 33.3 light-years (10.2 pc), to Beta Mensae, 794 light-years (243 pc): the farthest is 24 × farther than the nearest.