Diamond Cross Diamond Cross The Diamond Cross is an asterism in the southern constellation Carina. The Diamond Cross is composed of four bright stars: Beta, Theta, Upsilon and Omega Carinae. These four bright stars create an almost perfect diamond shape, hence the name "Diamond Cross". The entire asterism is visible to all observers south of 20°N latitude. It bears a striking resemblance to Crux (The Southern Cross) and the False Cross, and, like them, it lacks a central star in its cross pattern, creating a diamond-shaped or kite-like appearance. Both the Diamond Cross and the False Cross are sometimes mistaken for the
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