Constellations

This page is an explanation of constellations. For a complete list of all eighty-eight constellations click here.

Orion, One of the 88 modern constellations
of the night sky
Credit: Stellarium/KRC

There are eighty-eight constellations in the night sky although not all of them will be visible from the northern hemisphere. Originally a constellation was a depiction of an object or an animal or a character of mythology made by joining certain stars in the night sky together with imaginary lines.

Serpens (the serpent or snake) is the only constellation to be divided into two sections, Serpens Cauda (the tail) to the east of Ophiuchus, and Serpens Caput (the head) to the west. Although Cauda and Caput have been seperated by Ophiuchus they are regarded to be both one and the same constellation!

But in the early 20th century the I.A.U. (International Astronomical Union) created boundaries within which the constellations reside. So now, technically a constellation is actually an area of sky rather than a group of stars.

Many of the constellations we know today were created by the ancient Greeks showing heroes and characters of Greek mythology but there are also many 'modern' constellations as well depicting scientific instruments and navigational aids. Most of these are in the southern hemisphere.

Constellations exist only as works of the mind as the stars which make up constellations are in no way connected to each other. Think of constellations merely as a way of finding your way around the sky.