MensaMensa

What it looks like

Mensa was introduced by Lacaille in 1756 and named 'Mons Mensae' — Table Mountain — in honour of the Cape Town landmark beneath which he conducted his southern sky survey. It is the faintest of all 88 constellations by brightest star, and contains a large portion of the Large Magellanic Cloud, which spills across its northern border.

Brightest stars

Mensa is the faintest constellation in the sky — its brightest star, Alpha Mensae, reaches only magnitude 5.1.

Mythology and history

Mensa has no ancient mythology. It was created by Lacaille in 1756 and named after Table Mountain in South Africa, where he carried out his observations of the southern sky.

Table Mountain in the sky

Mensa is unique among the 88 constellations in being named after a real place on Earth. Lacaille, observing from Cape Town between 1751 and 1752, named it 'Mons Mensae' — Table Mountain — after the flat-topped landmark that dominates the city's skyline and under which he did much of his work. No other constellation has such a direct geographic reference. Because it lies so far south and contains few bright stars, Mensa is one of the least-known constellations, though the northern part of the Large Magellanic Cloud extends into it.

How to find it

Look between the Large Magellanic Cloud and the south celestial pole on summer evenings from the southern hemisphere.

• Find the Large Magellanic Cloud, then look south for Mensa.
• Very faint — a genuine test of dark-sky observing.
• Best from the southern hemisphere on summer and autumn evenings.

Key facts

Abbreviation

Men

Genitive

Mensae

Meaning

Table Mountain

Brightest star

Alpha Mensae

Main stars

4

Area rank

75th

Best visible

January

Declination

-75°

Meteor showers

—

Neighbours

Dorado, Hydrus, Octans, Chamaeleon, Volans

Deep-sky objects

Mensa contains part of the Large Magellanic Cloud, including the LMC's southern regions. It also contains the globular cluster NGC 1841, several faint galaxies, and parts of the Magellanic Bridge — the stream of gas connecting the two Magellanic Clouds.

Frequently asked questions

What does the constellation Mensa look like?

Mensa is a faint southern constellation named after Table Mountain in South Africa — the only constellation named after a real geographic feature on Earth.

What is the brightest star in Mensa?

The brightest star in Mensa is Alpha Mensae, shining at around magnitude 5.09.

When is Mensa best visible?

Mensa is best seen from southern hemisphere during January.

What is the story behind Mensa?

Mensa has no ancient mythology. It was created by Lacaille in 1756 and named after Table Mountain in South Africa, where he carried out his observations of the southern sky.

Which constellations are near Mensa?

Mensa borders Dorado, Hydrus, Octans, Chamaeleon and Volans.