Mensa
Mensa is a small constellation which lies close to the south celestial pole. Across much of the southern hemisphere it is circumpolar, but it appears highest in the evening sky in the months around December.
The name ‘Mensa’ means ‘table’ and refers to Table Mountain, close to Cape Town. It is the only constellation to be named after a real geographic feature on Earth, and was created by Nicolas Louis de Lacaille in 1756. He chose the name because Table Mountain overlooked his observing site when he was charting the southern sky.
Much later, the mountain also overlooked the site used by Sir John Herschel to scan the southern sky for nebulae in 1834–8.
Mensa has the dubious distinction of being the only constellation to contain no stars brighter than fifth magnitude – making it arguably the faintest of all the constellations.
It does, however, have some deep sky objects of interest. One of the Milky Way’s two dwarf companion galaxies, the Large Magellanic Cloud, touches its northern edge. Within this sky area, numerous open and globular clusters are visible.
In India, the constellation is known as ಸಾನು (Saanu).
Mensa contains:
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Stars
- α-Men (mag 5.1)
- γ-Men (mag 5.2)
- β-Men (mag 5.3)
- κ-Men (mag 5.4)
- θ-Men (mag 5.4)
- η-Men (mag 5.5)
- μ-Men (mag 5.5)
- ε-Men (mag 5.5)
- ζ-Men (mag 5.6)
- π-Men (mag 5.7)
- HD 22676 (mag 5.7)
- δ-Men (mag 5.7)
- ν-Men (mag 5.8)
- ξ-Men (mag 5.8)
- WX Men (mag 5.8)
- ι-Men (mag 6.0)
- HD 30479 (mag 6.0)
- TZ Men (mag 6.2)
- HD 33875 (mag 6.3)
- HD 31975 (mag 6.3)
- HD 33519 (mag 6.3)
- HD 23474 (mag 6.3)
- HD 35798 (mag 6.5)
- λ-Men (mag 6.5)
- HD 44447 (mag 6.6)
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Open Clusters
- NGC 1845 (mag 10.2)
- NGC 2031 (mag 10.8)
- NGC 2025 (mag 10.9)
- NGC 2134 (mag 11.1)
- NGC 1986 (mag 11.1)
- NGC 1711 (mag 11.1)
- NGC 2065 (mag 11.2)
- NGC 2203 (mag 11.3)
- NGC 2107 (mag 11.5)
- NGC 2051 (mag 11.7)
- NGC 2010 (mag 11.7)
- NGC 2056 (mag 11.8)
- NGC 1939 (mag 11.8)
- NGC 1944 (mag 11.8)
- NGC 2058 (mag 11.8)
- NGC 2038 (mag 11.9)
- NGC 2145 (mag 12.1)
- NGC 1823 (mag 12.1)
- NGC 2000 (mag 12.1)
- NGC 1959 (mag 12.2)
- NGC 2057 (mag 12.2)
- NGC 1766 (mag 12.2)
- IC 2146 (mag 12.4)
- NGC 1815 (mag 12.4)
- NGC 2111 (mag 12.4)
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Globular Clusters
-
Galaxy
View Mensa in 3D
Source: Wikipedia, in-the-sky.org
Image Courtesy: Sky&Telescope & IAU, Illustration Images linked from Urania's Mirror on Wikmedia Commons by Sidney Hall
Image Courtesy: Sky&Telescope & IAU, Illustration Images linked from Urania's Mirror on Wikmedia Commons by Sidney Hall