Looking at the cloudless night sky, see stars sparkling; from one star, you draw a line or a curve to another star, some more stars. Those lines can form lines of a letter (for example, the letter m). Almost since very ancient times, humans have done so and named groups of stars that they observe. That group of stars is called the constellation.
The names of the constellations we use today go back to ancient Roman times. These ancient Romans reused the earlier Greeks’ names; the ancient Greeks reused some of the earlier Babylonian names. The Babylonians named the constellations based on the shapes of their mythical animals, kings, queens, or heroes. The Greeks changed Babylon’s names to the names of their gods and heroes, such as Hec-quyen, O-he, and Peheke. The Romans changed the names of the gods of Greece to the names of their gods. However, some old names are still preserved. However, it isn’t easy to discern the shapes of the constellations based on their names. For example, in the constellation “angel,” the constellation “big dog,” constellation “puppy,” it is difficult to imagine a hawk, large dog, puppy in those constellations.
Approximately 150 years AD, the very famous astronomer of that time, Pleelene, listed 48 constellations that he knew. This list does not include all constellations visible in the sky. There are many points left blank. Later astronomers added many more constellations to Pileen’s list. Some constellations are named after astronomical applications such as “hexadecimal glass,” “compass,” “telescope.” Today, in the sky, astronomers list 58 constellations.
The constellation is a very wide expanse of space in the sky. For example, a star in the constellation can be envisioned as a city or town on a national map. The constellation boundaries are the same as the boundaries between countries, meaning that they are undulating, not as straight as the rulers. But since 1928, astronomers have traditionally drawn a straight line as a border for the constellations.