The Cygnus Enigma

The Cygnus Enigma

The Cygnus Enigma examines the link between megalithic passage-mound of Newgrange, the myths which relate to that eminent monument, and other interesting factors which together form a fascinating ancient mystery. In our investigation, we examined the relationship between the astronomical alignments of Newgrange and Fourknocks, the whooper swans which winter at Newgrange in large numbers, the constellation Cygnus and the numerous myths and stories about Newgrange relating to swans.

The fields near Newgrange provide a wintering ground for a large flock of whooper swans. The whoopers migrate to Ireland from Iceland for the winter months (which are warmer in this country) in large numbers. Somewhere in the region of 15,000 to 20,000 swans land at Co Donegal and disperse from there to wintering sites around Ireland. 

Newgrange is probably the only site in County Meath where whooper swans come in sizeable numbers each winter. The whooper swan population was first officially recorded at Newgrange in the Winter of 1966/'67, but both whoopers and Bewick’s swans were recorded feeding on large open meadows and bogs in Co. Meath in the last century. However, it is not known how long the birds have been coming to Ireland as statistics are unavailable for the preceeding centuries. 


Whooper swans at Newgrange
Whooper swans at Newgrange.


All the whooper swans which visit Ireland are from the breeding population in Iceland. The most recent available estimate of the size of this population, from a survey carried out in January 1995, was of 16,000 birds. The flock at Newgrange varies in size from year to year, ranging from as few as 30 birds to as many as 226, the highest number ever recorded at the site, in the winter of 1987/'88. In the spring of 2004, there were 45 birds at this site, along with a further 15 to 20 mute swans.

The autumn landfall for these birds is in County Donegal. They land in early October. From there, the birds disperse to sites widely distributed throughout Ireland.

There is a certain grace and beauty encapsulated in the flight of the swan unmatched by other species of the bird kingdom. Although awkward in take-off, which usually requires a long stretch of water or land to act as a "runway", once in flight the swan comes into its own.


Mute swan
A mute swan on the River Boyne. The mute swans are resident all year round. The whooper swans only come in winter.


The legend of Oengus and Caer

One of the most striking swan myths associated with Newgrange is the story of the romance of Oengus (also sometimes spelt Aonghus) and Caer. Oengus was a mythical chieftain of the Tuatha Dé Danann, who were the principal race of the otherworld – the gods – in ancient Irish mythology. He resided at Brú na Bóinne – the tumulus of Newgrange – and was often referred to as ‘Aonghus an Bhroga’. His father was the Dagda, the ‘good god’, a principal deity of the Tuatha Dé Danann, and his mother was Bóinn, or Bóann, the goddess of the River Boyne, which gets its name from her.

The story tells how Oengus fell madly in love with a maiden who visited him while he slept. She visited him in his dreams for a year, and all this time he could not touch her because she would disappear. His mother Bóinn searched Ireland for the maiden, but was unable to find her after a year of searching. Oengus enlisted the help of his father, the Dagda, who in turn sought out Bodb, who was the Tuatha Dé Danann king of Munster. Bodb revealed that the maiden was Caer Iobharmhéith, and brought Oengus to meet her at Loch Béal Dragan (The Lake of the Dragon's Mouth) in Tipperary. Bodb explained how Caer was from Sídh Uamhain, an "otherworld residence" in Connacht.

Caer’s father revealed to the Dagda that his daughter went in the forms of a bird and a girl on alternate years. The story, as related by Dr. Daithi Ó hÓgáin, continues: At the following Samhain (November) she would be a bird at Loch Béal Dragan, and the Dagda instructed Aonghus to go there and call her to him. He did so, and found her in the shape of a beautiful white swan, in the company of thrice fifty others. She went to him, and he too became a swan, and they embraced each other and flew three times around the lake.

They then flew together to Brugh na Bóinne and put the dwellers of that place to sleep with their beautiful singing. Caer remained with Oengus in the Brugh after that.

Unfortunately, no firm date can be put on the origin of this story. The same applies to many of the ancient Irish myths, which were only written down in Christian times, having survived until that time by word of mouth. Therefore even though the legend mentions Newgrange, and also swans, we cannot say whether this story comes from the distant epoch of Neolithic Ireland.

Gods from the sky

The gods themselves were a mythical race, who according to myth lived on earth, “some say in the north, others in the “southern isles of the world”.” But the earliest account tells us that the Tuatha de Danann, gods of the Gaels, “came from the sky.” 


The shapes of Newgrange and Cygnus are cruciform.
Newgrange and Cygnus are both cruciform.


Newgrange and the cross

It was the presence of the whooper swans near Newgrange which put us on the scent of the mystery. We began by comparing the shape of Cygnus with the ground plans of the Newgrange chamber. There were striking comparisons. The chamber of Newgrange is cruciform. The swan constellation that we know today as Cygnus is also cross-shaped. 

The passage and the constellation

The cross shape of the constellation does not form two perfectly straight intersecting lines. The “east-west line” of the formation is crooked because the central star, Sadr (Gamma g Cygni) was off line. The longer “north-south line”, running from Deneb at the north to Albireo at the south, also deviated, and is seen to bend towards Sadr and back again towards the star Eta (h) Cygni. This bending of the north-south line is actually quite appropriate when viewed in the context of the Newgrange passage, which kinks or veers slightly to the east and back again as it winds towards the entrance.

The star Albireo, which represents the beak of the swan, is yellow in colour, just like the beaks of the whooper swans. In the context of the Newgrange passage, Albireo lay in the passage towards the south. This, we remembered, was the direction from which the (yellow/golden) sun’s rays penetrated the passage and chamber on the morning of winter solstice.


Fourknocks chamber
A view of the chamber of Fourknocks.


Newgrange and Fourknocks

On the dawn of the shortest day of the year, about four and a half minutes after the sun rises over Roughgrange Hill, or Red Mountain, the sun shines into the roofbox over the entrance to Síd in Broga (Newgrange) and into the passage, where it illuminates the chamber which is 18 metres inside the mound. This precisely calculated event, which undoubtedly involved huge effort for the Neolithic community which constructed the mound and its passage, is now the most heralded cosmic event in the modern archaeological world, and is known about right across the globe.

A much smaller Neolithic mound, called Fourknocks, lies 15km southeast of Newgrange. This mound lies directly on the path of this winter solstice azimuth from Newgrange. The best way to visualise it is this: as the last beam of sun is retreating from the chamber of Newgrange on winter solstice, imagine you could follow that beam back towards the sun. You would fly along the sun beam, through the passage of Newgrange and out through the sky window or roof box. If you followed that beam towards the sun for 15km, you would be directly overhead the Fourknocks mound. It would seem that Fourknocks may have been positioned in such a way as to form a special alignment with Newgrange and the winter solstice sun.

What we wanted to resolve was whether the passage of Fourknocks was aligned on a significant star, or constellation, given that its azimuth put it too far north of the sun's midsummer rising position, and the major northerly standstill of the moon.

The "window" of visibility from the passage of Fourknocks sits over the western slopes of the hill of Mullaghteeling, and in the distance can be seen some of the peaks of the Mourne and Cooley Mountains. When we consulted our computer software to reconstruct the skies over Neolithic Ireland, we wanted to view this area of sky just as the mound builders would have seen it at around the time the great mound at Newgrange was constructed.

Using SkyGlobe, a computer program designed to allow the user to see the positions of the sun, moon, planets and stars at any moment in time, we honed in on the critical time when we felt we would see something important – not the later end of the Fourknocks construction window, but rather the earlier possible date for its construction – 3000BC – not long after the probable completion of Newgrange. We centred on the year 3000BC. Then we watched as SkyGlobe performed a sequential, simulated movement, of the stars.

As the sequence progressed we watched with anticipation as some relatively faint and obscure stars and constellations passed close to our sky "window". Among the close grazers were Serpens Caput, a comparatively faint constellation, a magnitude 3.3 star in Lyra called Sulafat, Epsilon Cassiopeiae with a brightness of 3.4, a magnitude 2.6 star called Zosma in Leo, and a magnitude 3 star in Virgo called Vindemiatrix. But one star, alone in its brightness and its positioning in the centre of our window, dominated.


Cygnus due north
Cygnus due north at the time Fourknocks was built.


I watched Deneb, the bright tail star of the swan constellation, Cygnus, skim the horizon due north and then rise up slowly again, passing right through our neolithic "sky window". The very constellation which we had associated through various lines of investigation with the Newgrange mound, was now a found to be a target of the Fourknocks construct. This bright star, the main star of Cygnus, must have been a beacon of light in the dark northern skies of the Neolithic.

The giant spinning top

Cygnus, and more specifically Deneb, are important for two astronomical reasons, and we believe Deneb was the target of the Newgrange-Fourknocks astronomical construct because of this. The Newgrange passage points to Fourknocks, although neither mound can be seen from the other. Interestingly, around the epoch 3000BC, Deneb acts as a marker for the position of the sun at the winter solstice. On the night of the midwinter solstice, Deneb marks the location of the sun from the time the sun sets until the time the sun rises plus or minus the minutes it takes Deneb to come out into the darkening sky. So observers at either mound could track the position of the sun below the horizon using Deneb as their guide.

The second significance of Deneb relates to precession of the equinoxes. Throughout the entire 25,920-year cycle of precession, Deneb remains mostly a circumpolar object, never setting below the horizon and being visible to observers at the latitude of Newgrange and Fourknocks every night of the year. But interestingly in the epoch 3000 to 2500BC, Deneb is at its lowest point in the entire cycle. It grazes the horizon, and just about sets below the horizon at due north briefly during this time, before rising again.

The fact that Deneb marks the location of the below-horizon winter solstice sun is of major significance to our idea that the passage of Newgrange was laid out to resemble the shape of Cygnus. The fact that this Cygnus-shaped passage points to Fourknocks gives us an indication that Fourknocks might have been part of a complex astronomical alignment. 


Milky Way on horizon
A view from Stellarium showing the Milky Way on the entire horizon c3000BC. Cygnus is rising in the north.


One further facet of the apparent alignment is that, just as Deneb is rising again off the horizon, and is visible to an observer in the end recess of the chamber of Fourknocks, the Milky Way galaxy is wrapped around the entire horizon, from north to east to south to west to north again. The entire bright band of the Milky Way is visible on the horizon. This is something that only happened in that epoch, and due to precession it no longer happens today.

The great monument of Newgrange has a giant wall of quartz around it. Was this, perhaps, representative of the Milky Way? The River Boyne loops around the Brú na Bóinne complex of monuments. One of the Irish names for the Milky Way was Bealach/Bóthar na Bó Finne, the Way/Road of the White Cow.


Swan on Boyne
A (mute) swan on the River Boyne.


Swans in mythology

Further stories about Newgrange contain references to swans with possible astronomical undertones. The most striking of these is the conception of the great hero Cúchulainn at Newgrange by the deity of light, Lugh. But there are many stories containing swans.

The story of how Cúchulainn (known in his youth as Sétanta) was begotten tells how Conchobor and the nobles of Ulster were at Emhain Macha. A flock of swans came to the plain and ate all the grass and plants out of the ground. The Ulstermen were angry at this and chased the birds away in their chariots.

Conchobor mounted his chariot with his sister, Dechtine. The birds flew to Breg Plain, which is in modern Ireland the eastern part of County Meath and contains all the major neolithic sites of the Boyne Valley. The story tells how there were "nine score" birds with a silver chain between each couple. Each score went in its own flight with two birds out in front of each flight.

The chasing party pressed on until they reached Brug on the Bóann river (Newgrange), and night overtook them there. It snowed heavily upon them, indicating that the story took place in midwinter, and Conchobor told his people to seek shelter.

It is during this fascinating story that Dechtine is visited in a dream by Lugh, one of the supreme deities of the ancient Irish, while she is inside Newgrange. After this she is conceived of Setanta, who later becomes Cuchulainn, the best-known hero of Irish mythology.

The story of the Children of Lir, a tragedy in which four children are changed into swans for 900 years, moved the Milesian invaders to enact a special law when they came to Ireland. The Milesian chiefs made it law that no-one should harm a swan in Ireland from that day forth.


Cygnus and Draco
Cygnus is located near the head of the Dragon (Draco). The Lake of the Dragon's Mouth, perhaps?


The dragon

Another aspect of the Aonghus-Caer romance is interesting. It is the reference to the "Lake of the Dragon's Mouth", where Aonghus found Caer. This could be a possible reference to the constellation of Draco, which is a prominent constellation in the northern hemisphere of the sky.

The constellation is particularly relevant in the Neolithic period, because the main star of Draco, called Thuban, was the pole star for a few hundred years around the date 2,800BC. It is also fascinating to our story in light of the fact that Cygnus the constellation is located very close to the head of the dragon in the sky.

There is also a story about a great mythical 'monster' which was killed at Newgrange. The story relates how "when the men of Erin broke the limbs of the Matae, the monster that was slain on the Liacc Benn in the Brug of Mac Oc, they threw it limb by limb into the Boyne, and its shinbone (colptha) got to Inber Colptha ("the estuary of the Boyne"), whence "Inber Colptha" is said, and the hurdle (clíath) of its frame (i.e., its breast) went along the sea following the coast of Ireland until it reached yon ford (áth); whence "Ath Cliath" is said."

In my book Mythical Ireland: New Light on the Ancient Past, I discuss the possibility that the story of the Mata might relate to the constellation Draco.


Larry Lenehan, Irish East Coast Bird Report, 1995
Dr. Daithi O hOgain, Myth, Legend and Romance, An Encyclopedia of the Irish Folk Tradition.
Charles Squire, Celtic Myth & Legend, Newcastle Publishing, 1975.
Denton P. Walter, Astronomy & Space magazine, August 1997.
Claire O’Kelly, Illustrated Guide to Newgrange, 1967.
George Eogan, Knowth and the passage-tombs of Ireland, Thames and Hudson, 1986.
Tom P. Cross & Clark Harris Slover, Ancient Irish Tales, Barnes & Noble, 1996 (1936).
Martin Brennan, The Stars and the Stones, Thames & Hudson, 1984.
Thomas Kinsella, The Táin, Oxford University Press, 1969.
Graham Hancock, Heaven's Mirror - Quest for the Lost Civilisation, 1998.

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1 comment

Brilliant article. Thank you for sharing. There was an article on this website years ago that I have been trying to find, it showed the leylines in Tara, it was a drawing and in colour. Is there any chance you still have it there or could I have a copy of it please? It’s very important as it will help with Gridwork. Thank you 😊

Daria Flanagan

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