The current list of 88 constellations recognised by the International Astronomical Union^[1] since 1922^[2] is based on those listed by Claudius Ptolemy, Greek-speaking mathematician, geographer, astronomer, and astrologer who lived in the Hellenistic culture of Roman Egypt. He may have been a Hellenized Egyptian, but he was probably of Greek ancestry, although no description of his family background or physical appearance exists, though it is likely he was born in Egypt, probably in or near Alexandria.

Greek astronomy was built on Mesopotamian foundations. They defined the Zodiac and at least another 18 constellations taken over or adapted by the Greeks:

The earliest direct evidence for the constellations comes from inscribed stones and clay writing tablets dug up in Mesopotamia (within modern Iraq)... It appears that the bulk of the Mesopotamian constellations were created within a relatively short interval from around 1300 to 1000 B.C...

The Mesopotamian groupings turn up in many of the classical Greek constellations. The stars of the Greek Capricorn and Gemini, for example, were known to the Assyrians by similar names - the Goat-Fish and the Great Twins. A total of 20 constellations are straight copies. Another 10 have the same stars but different names. The Assyrian Hired Man and the Swallow, for instance, were renamed Aries and Pisces.^[3]

In more recent times, Ptolemy's list has been added to in order to fill gaps between Ptolemy's patterns. Most of the northern sky was filled in by Petrus Plancius and Johannes Hevelius.

The constellations around the South Pole were not observable by the Greeks. Twelve were observed by Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman in the end of sixteenth century and depicted by Johann Bayer in his star atlas Uranometria of 1603. Several more were created by Nicolas Louis de Lacaille in his star catalogue, published in 1756.

Other proposed constellations didn't make the cut, most notably Quadrans (now part of between Boötes and Draco) for which the Quadrantid meteors are named. Also the ancient constellation Argo Navis was so big that it was broken up into several different constellations, for the convenience of stellar cartographers.

References

1. ^ International Astronomical Union. "The Constellations".
2. ^ Ian Ridpath. "Constellation names, abbreviations and sizes".
3. ^ The Origin of the Greek Constellations, by Bradley E. Schaefer. Scientific American, November 2006.)

See also

• Former constellations
• List of constellations
• Star Names: Their Lore and Meaning, by Richard Hinckley Allen
• Star Tales by Ian Ridpath