In a pre-industrial society, stars and constellations had more impact on the viewer because there was less light pollution. Pictures could be traced, paths, and stories, all providing a commonality among members of a tribe or society. One common example is the constellation of the Big Dipper, or Ursa Major, imagined by many ancient cultures to be an animal hunters pursued across the sky. So many, in fact, that the path of those stories has been traced from the Americas back into Asia.
Tolkien himself included the Big Dipper in his works, referring to it as The Plow.
In the Western world, constellations are a hodgepodge from different eras. The Greek period shaped our skies the most, with some, such as the creatures of the Zodiac, dating from older sources such as Babylon and Sumeria. A fresh round of constellation creation occurred in the late 1600s by Petrius Plancius, who contributed the Southern hemisphere Volans, Musca, Pavo, and others named for various flying and water creatures. In the 17th century Nicolas Louis de Lacaille and Johannes Hevelius made up some more to fill in blank spaces on the star charts. Unfortunately, instead of memorable creations like Pegasus and Sagittarius, most of these were of dull objects like Horologium (the clock) and Sextans (the Sextant.)
Non-Western societies had different views of the skies. Australian aboriginals formed some constellations from star absences, seeing, for example, an emu in the dark sections of the Milky Way.
Chinese cosmology had an ordered view of four divine creatures, temples, palaces, and armies.
The final authority on modern constellations, however, is the International Astronomical Union, and their list tops out at 88. Those constellations that didn’t make the cut include Felis, the Cat; Bufo, the Toad; Hirudo the Leech and Limax the Slug; Solarium the Sundial; and Cor Caroli Regis Martyris, or Charles’ Heart, an attempt to flatter Charles I of England.
Here’s a list of randomly generated constellations to give inspiration for your own work.
Karnus, the Dancing Jackel
The Celestial Ash Tree, formed by the stars Ulateuse, Tergraz, Talithtor, and Julsud
Zarra, the Manticore
The Summer Diamond
Shaunus, the Sleeping Shipwright
Phridules the Fish
The Wise Man
The Fawn-headed Acrobat
The Beetle-headed Fool
Belium the Drover
The Silent Scorpion
The Royal Staff
Alraphone, the Skybound Nightingale
The Dauntless Minstrel
Isgnorabus, the Sextant
The Golden Glaive
Charzar, the Heavenly Smelting Iron
Zenium the Crone
The Holy Quince tree
The Devil’s Bridge
Taphnus the Dogfish
Torstrixus, the Poisoned Cup
The Winter Circle
The Autumn Pentacle, consisting of the five stars Forbaran, Kandash, Gorabuel, Karlschaat and Othmal
Udales the Bat