Friday, September 18, 2015

The Ten Star Pillars of Polynesia




The Polynesians, or more particularly the Tahitians, had a very clear structure of the sky and the pathways of the sun, planets and stars. The conception was that the sky was a dome resting on the rim of the earth. The space above the earth was often divided into three zones, the upper purely celestial zone, the lower the terrestrial zone and in the middle the air space zone. The heavens resting on the earth had supports consisting of ten great pillars around the horizon that held the sky dome in place. The sun rose each day and reached its zenith in mid-summer. The star Rigel in the constellation Orion is used by Maori as a synonym for Zenith but since New Zealand is 35 degrees or more south of the equator this usage must relate to the time when Maori were nearer the equator prior to migration south. Two lines parallel to the celestial equator marking the southern and northern limit of the sun in declination – the tropics of Capricorn and Cancer- were the limits of the fixed stars or planets. Outside that zone were the stars of space and the highways of the navigation stars.
The meridian line through the poles and passing through the zenith divided the sky into two halves, the stars rose in the eastern half and then descended the much travelled highway back into the ocean.  The Tahitians did not use four cardinal points but had eight that were associated with the eight tentacles of the octopus separated the earth from the sky. They not indicators of direction however.  
The Tahitian compass had cardinal points associated with methods of tracking- the winds, the sun and the geographical centre of an island.
The imaginary line around the equator had two parallel lines that marked the northern and southern limits of the sun’s annual passage across the tropics. Within that zone the fixed stars (planets) had their home. Outside that zone were the stars of space.



The astronomers noted the rising point of the sun every ten days and observed the eastern constellations just before dawn and must have formed a concept of the constellations similar to the zodiac constellations of the Europeans, through which the sun passed on its annual journey. When Pleiades was at its northern limit of rising the sun reached its summer solstice and they celebrated the New Year. However the star groupings were not the same as the 12 of the zodiac.  The Polynesians recognised pathways of stars and used major stars within their constellations to locate the star paths.
The Polynesians recognised the pathways of the stars of the constellations as “the great highways of the navigation stars” and those stars that rose in succession were on a rope and rose from the same “pit”.

Star Pathways

To the ancient Polynesian navigator the sky, especially the night sky, was the compass, chart and chronometer. He could point to any star and tell you which islands that the star would lead you, if you steered your canoe to the point where it rose or set at the horizon. He could point to the other stars which followed it along the same diurnal path across the sky and which could be used as bow star after it had set.  
The skilled navigators knew which stars passed though the zenith of a certain island. Thus if they sailed north or south, as the case maybe, with the tradewinds, until such stars passed through their zenith during the night, they knew they were in the right latitude and would then change course to sail along the latitude line to make landfall.

An Island’s Zenith Star

The Tahitians had a zenith star for all their islands  If the island target is distant a zenith star can give useful information. Consider a voyage to Hawaiii from Tahiti – some 4000 km – Arcturus at 19° North  would be zenith for the southern end of the Hawaii Islands chain. A navigator could sail north until Arcturus just passed over his zenith to the south then turn and sail west at constant latitude. The Hawaiin Islands form a wide enough target that when running down a latitude line an island would be intercepted. While every island is identified by its zenith star ‘avei’a, but the single star is not usually used as a star to find and navigate to.


Star Paths

In any particular latitude, stars rise and set at the same point on the horizon throughout the year. Beyond the tropics, stars rise and set obliquely, describing a circle around the celestial pole.  Close to the equator, their motion is nearly vertical.
Stars that set in the west or have risen too high in the east to be good direction indicators are replaced by new ones on the same bearing. The succession of stars is called a “star path”.  A refinement of the star path is the concept of a star compass where the direction points are marked by the rising and setting points of stars on the horizon.
Bearings from a particular island to another must be known and incorportated into the compass. The memorization of the stars required sophisticated mental cartography as mnemonic devices to arrange their knowledge of celestital and terrestial geography into organized bodies of data.

Ten Pillars

The organisation of mnemonic devices is seen in a Chant of Rua-Nui from Tahiti that was recorded by Orsmond and published by his grandaughter Teuira Henry. The Chant relates to Ten Pillars that prop up the sky. Each Pillar has an associated Star as follows:
Antares is the entrance pillar of the dome of the sky,
Aldebaran is the pillar to blacken or tattoo by,
Spica is the pillar of perfect purity,
Dubhe is the Pillar to guard by,
Alphard is the pillar to debate by,
Arcturus is the pillar to stand by,
Procyon is the pillar for elocution,
Betelgeuse is the pillar to sit by,
Phact is the pillar of exit,
Polaris is the pillar to fish by in the boundary of the sky.
The sky is said to have been low down formerly, and propped up from the earth with pillars in the order given.  The Pillars in a domed house could have been associated with the navigation school in Tahiti and the students used the Pillars in the order given in a memory sequence.
The Polynesians did not have the ability to project their mind into the sky and look down or form a map in their mind of what they saw or visualize a canoe moving across the surface. They saw the sky and its stars moving across their island and canoe. They recognized the stars as coordinates for their islands.


The Rua

In mythology when the sky and earth were separated from the tentacles of the Octopus by the god Tane and then lifted the sky with 10 pillars. At the border of the sky the waters of the ocean fall into the abyss (rua) from which emerge the winds and the stars.  Each series of aligned stars that emerge from the horizon to the east are called rua. There are 10 identified by their azimuth and they form a star compass rua fetu.

These rua fetu then run through the heavenly vault keeping their figure aligned and plotting paths in the sky before sinking in the West. Ten stars of the first magnitude help to identify a ‘celestial’ pillar when they are at their peak. These stars in turn rise to the peak and descend to the West. Aligned at their peak with another star located around the celestial poles (Duhbe) which in turn determines a celestial pillar coinciding with the celestial meridian.

Five planets were recognised: Venus and Jupiter, each as a Morning and Evening star, Mars, Mercury and Saturn.

The stars are divided into three classes:
‘Avei’a a guide star which passes through the zenith of an island and allows it to be identified.
Ana “star marker” is one at its peak that can identify a pillar Pou.
Ta'urua “star headlight” that which on the horizon can identify a star path Rua.

Stars identified: Capella, Alderman, Spica, Altair, Deneb, Vega, Achernar, Castor, Pollux, Rigel, Antares, Polaris, Arcturus, Sirius.
Stars were grouped according to a figure as in the Western constellations: Hui-fetu or Hui-tarava,
Or aligned according to a star path: Pou (celestial pillar) and Rua (celestial star path).

The ten Pou Pillars were identified the the repsective ‘Ana’ pointer stars- (with recent translation adjustments):
Scorpio : Antares
Libra : Zuben-Eschamali
Leo : Regulas
Ursa Major : Dubhe
Hydra : Alphard
Bootes : Arcturus
Canis Minor : Procyon
Orion : Betelgeuse
Columba : Phact

Ursa Minor : Polaris.

The ten Rua are identified by their Ta’urua pointer stars
Cygnus : Deneb
Orion North : Betelgeuse
Orion’s Belt : 3 stars
Hydra North : Alphard
Canis Major: Sirius
Piscis Austrinis : Fomulhaut
Grus : Alnair
Argo : Canopus
And the Sun at winter solstice.

The two planets Venus and Jupiter  indicated the path traced by the planets – the ecliptic.

If we sail South to North we cross all Rua one after another. Every rua draws a line on the heavens which is the same as a latitude lines, but of course irregular.
The sky dome is crossed by 10 ‘Ana stars each following in turn to the climax. The line joining one of them, located at the peak to the star Dubhe located to the north is simialr to the meridian. There are enough ‘Ana stars to view the meridian all night.  In the southern hemisphere, to navigate from South to North, we align the body of our canoe on the axis formed by a star ‘Ana at its peak with Duhbe located in the North. As soon as the Ana passes the Zenith choose the following stars from east rising to the Zenith. In the northern hemisphere choose Polaris instead of Duhbe.
A Rua is a series of stars aligned from east to west idetified by its major star a Ta’urua.
A Pou is the meridian which starting from a star ‘Ana at its peak joined to ‘Dubhe’ near the North Pole.
The Rua and Pou are assimilated with latitudes and  longitudes. 

Most of this blog has been extracted from:
Jean-Claude TERIIEROOITERAI (2013)
Mythes, astronomie, découpage du temps et navigation traditionnelle : l’héritage océanien contenu dans les mots de la langue tahitienne.

PhD Thesis 2013, UNIVERSITÉ DE LA POLYNÉSIE FRANCAISE