- Southern celestial hemisphere (Wikipedia)
The southern celestial hemisphere, also called the Southern Sky, is the southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, appears to rotate westward around a polar axis due to Earth’s rotation.
- Mensa is a constellation in the Southern Celestial Hemisphere near the south celestial pole, one of fourteen constellations drawn up in the 18th century by French astronomer Nicolas-Louis de Lacaille. Its name is Latin for table, though it originally commemorated Table Mountain and was known as “Mons Mensae”. One of the eighty-eight constellations designated by the International Astronomical Union (IAU), it covers a keystone-shaped wedge of sky 153.5 square degrees in area. Other than the south polar constellation of Octans, it is the most southerly of constellations and is observable only south of the 5th parallel of the Northern Hemisphere.
- Beta Trianguli Australis (stars.astro.illinois.edu)
BETA TRA (Beta Trianguli Australis). While not a dramatic star, third magnitude (2.85) Beta TrA, the number two star of Triangulum Australe, the Southern Triangle, is still so bright – well in the top 150 – that it surely deserves recognition, especially since TrA itself is a nice, bright constellation.
