Crux to a point close to the Southern Celestial Pole. Alternatively, if a line is constructed perpendicularly between Alpha Centauri and Beta Centauri, the point where the above-mentioned line and this line intersect marks the Southern Celestial Pole. Another way to find south, strike line through Gacrux and Acrux, 4 1/2 times the distance between Gacrux and Acrux, directly below that point is south. The two stars of Alpha and Beta Centauri are often referred to as the "Southern Pointers" or just "The Pointers", allowing people to easily find the asterism of the Southern Cross or the constellation of Crux. Very
Crux the Coalsack Nebula. The stars within Crux were known to the Ancient Greeks, where Ptolemy regarded them as part of the constellation Centaurus. They were entirely visible as far north as Britain in the fourth millennium BC. However, the precession of the equinoxes gradually lowered the stars below the European horizon, and they were eventually forgotten by the inhabitants of northern latitudes. By 400 AD, most of the stars in the constellation we now call Crux never rose above the horizon of Athens. The 15th century Venetian navigator Alvise Cadamosto made note of what was probably the Southern Cross on