Asterisms, Constellations and the Zodiac

Asterisms are not part of the official (IAU) constellations, but contain easy recognizable bright stars like the big and little dipper. This two Asterisms are part of the star constellations Ursa Major and Ursa Minor. Seasonal Asterisms are the Spring Triangle (Regulus, Spica and Arcturus), Summer Triangle (Altair, Deneb and Vega), Autumn Rectangle (Pegasus) and Winter Hexagon (Rigel, Sirius, Procyon, Pollux, Capella and Aldebaran). The whole sky, as seen from earth, is organized in 88 star constellations. The Zodiac contains 12 star constellations, sometimes also the Ophiuchus (serpent-bearer).