What Is A Constellation?

Looking at the stars, we trace out squares, letters, and other familiar figures. All over the world, people long ago did this and named the group of stars they observed. This group of stars is called “a constellation”, from the Latin term meaning “star” or (Stella and together).

Since the times of the Romans and from the even more ancient Greeks, the names of the constellations have come down to us. The Greeks inherited some knowledge about stars from Babylonians. They named some of their stars after animals, Kings, Queens, and heroes of their myths. The Greeks changed many of the Babylonian names to the names of their own heroes such as, – Orion, Hercules, and Perseus. Further changes were made by Romans, and the same ancient names are still used. The figure that suggested the name is not easy to make in the sky. To cite a few instances – Aguila is the eagle, Canis Minor, and Canis Major are little and big dogs, for scales the Libra. It is noticed that the constellations do not look much like these figures to us.

The famous astronomer Ptolemy in about the year 150 AD, listed 48 constellations that he had known. The list did not cover the entire sky as there were many blank spots left out. This list was later on supplemented by others. The later constellations are named for scientific instruments, namely – Sextant, Compasses, and the Micro-scope. The list now with the astronomers is for 88 constellations in the sky.

A constellation is actually an area in the sky. Every star falls in one constellation or the other, like a city in a state in the United States. The boundaries of the constellations used to be irregular. Many had curved lines. It was in the year 1928, astronomers took a decision to straighten the outline of the constellations.