The Origin of the Constellations


Constellations of various arrangements have been known since the first human settlements, and no doubt extend beyond our knowledge of record time into that of prehistory. To the earliest sky observers, the many visible stars to the naked-eye across the heavens have only appeared as tiny unreachable pinpoints of light randomly each scattered across in the inky blackness of firmament. There are seemingly innumerable numbers of stars, which are seemingly to many to totally count, however, across the whole sky there are really no more than about 6,500 stars visible, and only roughly half of these are seen at any one time above the horizon or hemisphere of the observer.

As all these stars would be impossible to named individually, so the bright naked-eye stars were broken into useful smaller manageable groups called constellations. Most of these familiar star patterns represent or depict the renown Roman or Greek classical gods, heroes and heroines, or animals. Some are human-made objects, including musical instruments, like the lyre (Lyra), scales (Libra) and altars (Ara), or microscopes (Microscopium) and telescopes (Telescopium), etc. Yet in truth, many observed constellations were not just restricted to Greeks or Romans, but have been traditionally used in other cultures, like the Australian Aboriginals, American Indians and seafaring Polynesians. They have also been created in regions in China, Mesopotamia, South America and India. This particular perspective is quite unlike the usual western bias we have historically adopted.

The Ancient Constellations

From the Ancient Chinese perspective, their culture has recognised and held various important constellations for the longest time — spanning several millennia. From the 5th Century B.C., twenty-eight constellations, known as lunar mansions, were used. These followed the same path of the ecliptic, in which the Sun, Moon and planets follow, but instead, occupy the places based on the daily movement of the Moon. They were further divided into four seasons, each with their own main palaces, making seven constellations per season. In total, including the lunar mansions, the Chinese adopted about ninety constellations around 150 B.C. By about 400 A.D., the number of constellations increase to 284! This appears on an ancient star chart centred on the north celestial pole with some 1,460 stars. It is interesting that Chinese astronomers did not divide the stars into large constellations —; and they looked nothing like our familiar Western patterns. Similar usage of these Eastern constellations soon spread across Japan, Korea and other south-east Asian countries. These Chinese constellation are still in use within China, alongside the internationally agreed eighty-eight modern constellation.

In India during the 5th Century AD, the names of stars and constellations fell under the Hindi or Vedic mythology, whose main twenty-seven groups were known as nakastra, plural naksatras.

Even older were the Egyptian constellations, which were mostly based on their important gods, like Seth and Thoth, and various of the venerated animals that they worshipped, like the lion, the crane or ibis, the crocodile, baboon and the hippopotamus. We know of thirty-six principle Egyptian groups that date to 1,100 B.C., that include the northern constellations of Ursa Major and Orion.

Older still were the first recorded constellations of ancient Mesopotamia, now placed in southern Iraq. These star patterns are established around the time of the first cities, techniques in agriculture, and language; whose region occupied the once fertile delta region of both the Tigris and Euphrates rivers. Many of these constellation go back as far as the Akkadian and Sumerian civilisations around 3,500 B.C. Many of these groups were later adopted by the Greeks, and include Scorpion, Orion, the bull (Taurus) and the lion (Leo.) Here also derives the main twelve constellations of the zodiac, being the path of the Sun, Moon and planets across the sky. The zodiac itself dates back earlier than about 2,000 B.C., whose appearance has been traditional associated with the year being importantly divided up into twelve months for the first calendars. By 1,000 B.C., the Mesopotamians had over sixty main constellations in common use.

The Classical Constellations

All forty-eight constellations originated from classical antiquity but most of the southern ones were more recently added from the 15th Century. Today eighty-eight standard constellations are now officially recognised and internationally agreed upon. At one time, the various constellations differed between the various countries throughout the world, which at one time or another, totalled as many as one-hundred-thirty (130) having common usage. Some of these groups were later classified as asterisms or subgroups of the constellations, that are similar to the particular part of an object or anatomical part assigned to the constellation. More than one-hundred twenty-seven (127) asterisms are commonly recognised. I.e. The Pleiades or Seven Sisters, The Hyades or the Square of Pegasus. From our southern hemisphere, there is; The False Cross, Orions mid-centre known as The Pot — which in the northern skies is called Venuss Mirror.

Many of the southern Milky Way constellations were once contained in the original classical mega-constellation of Argo Navis, that at one time covered the entire southern sky below the horizon of the Europeans. Argo Navis was later subdivided into far more manageable pieces by Nicolas Louis de Lacaillé, who also named another fourteen southern constellations, with thirteen being recognised today. Most of these remain the brightest and the most prominent southern constellations. Later in the 16th Century, both the Dutch navigators Pieter Keyser and Frederick de Houtman named twelve other southern constellations, while in the 17th Century Johann Bayer and Johannes Hevelius divided the rest. Many of these new names of these constellations are now not recognised, many are still in use.

Formulation of the Modern Constellations

Originally the constellations had no real defined boundaries, except for the interpretive head or foot of any particular group. It was not until 1925 that the then new International Astronomical Union (I.A.U.) — the governing body for deciding astronomical nomenclature and naming systems, and to adopt a specified internationally agreed position and subdivision of the constellation boundaries. The initial work on these constellations was commissioned by the I.A.U., who employed the independent French draughtsman, Eugene Delporte (1882-1953). Delporte adopted the northern boundaries originally established by Johann Bode, which were set for the beginning epoch of 1st January 1875. Towards the southern section of the sky, around about the same time, was mainly adopted using recommendation of Benjamin Gould. Delporte draft selections were to be only slightly modified, with the final version becoming all the constellation boundaries that have remained till this day. All the stars, including celestial or deep sky objects contained with in those boundaries became assigned to that constellation. (An English translation of the introduction to Delporte published work from French, and the discussion about the document, see the Scientific Demarcation Of The Constellations (Tables And Charts).)

However, one significant change to these boundaries has been the precession of the equinoxes, which slowly changes the earthly-based stellar positions throughout the centuries. This also changes the fixed constellation boundaries which are slowly being twisted askew. Looking at any detailed star chart, the boundaries in some places of the sky are no longer properly align north to south. This id due to the changing positions of the outlines in both right ascensions and declinations. In some cases, including Pavo, Triangulum Australe and the southern boundary of Dorado — that also passes through the Large Magellanic Cloud (LMC), these distortions are obvious and acute. In the distant future these boundaries may have to be redefined, thus changing the recognised constellations again.

All eight-eight selected constellations were from the most common used groups at the time. (See Index of the Constellations. ) This official list was first adopted by the IAU in 1922. Some realistic changes were adopted, such as officially divided Argo Navis into its component parts — deemed too large to properly name and number the stars it contained. Argo Navis is now the constellations of Vela, Puppis, Carina and Pyxis.

Other changes were not adopted. Some astronomers, for example, also wanted to include both the Small and Large Magellanic Clouds (SMC & LMC) as constellations in their own right — to be called Nebecula Major (NMa) and Nebecula Minor (NMi). Changing them into constellations were again formally suggested in 1964 (Trans.IAU., XII B, p.269.) but this was not been commonly adapted, but it would have been if everyone started used it! Few did. An example was the attempted popularising by E.J. Hartung with his 1968 release of Astronomical Objects for Southern Telescopes (AOST1) and the update in 1994 (AOST2). Nevertheless, this recommendation was never formally accepted by the I.A.U, so they had to remain as mere odd-named asterisms especially in the even light that they are really galaxies — small companions to our Milky Way Galaxy.

For the northern constellation from antiquity, only the constellation of Antinous was the only one deleted. Several popular constellations of the time were also removed. A short list of some of these, which sometimes appear in older books is given below. (Table 2)


[1] Admittedly, there are slightly more visible in the southern hemisphere, mainly because the Milky Way in Sagittarius is well south of the skys equator — the aequator.


Last Update : 5th December 2014

Southern Astronomical Delights © (2014)

For any problems with this Website or Document please e-mail me.