Crux Crux Crux is a constellation located in the southern sky in a bright portion of the Milky Way. It is among the most easily distinguished constellations, as all of its four main stars have an apparent visual magnitude brighter than +2.8, even though it is the smallest of all 88 modern constellations. Its name is Latin for cross, and it is dominated by a cross-shaped or kite-like asterism that is commonly known as the Southern Cross. Predominating is the first-magnitude blue-white star of Alpha Crucis or Acrux, being the constellation's brightest and most southerly member. Crux is followed by four
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