Göbekli Tepe and the Rebirth of Sirius
An examination of the night sky during the epoch of Göbekli Tepe's construction shows that the star Sirius was completely unsuitable for star alignments at this time.
Summary: Göbekli Tepe is the site of a series of stone enclosures built during the tenth and ninth millennia BC on an isolated mountaintop in southeast Anatolia (Turkish Asia Minor). Speculation has mounted regarding their orientation towards stellar objects, with Orion and Cygnus having already been proposed. Sirius is the latest star to be put forward as the primary focus of key monuments at the site. Yet such a conclusion is thwart with problems, not only in connection with the faint appearance and feeble movement of the star during the epoch in question, c. 9500-9000 BC, but also with respect to the orientation and layout of the enclosures themselves. Instead of being orientated to the south, the direction of Sirius, the enclosures are more likely directed to the north, the direction of liminal activities since the Upper Paleolithic age. In this respect, a more suitable stellar candidate for the orientation of the enclosures is Deneb, the brightest star in Cygnus, which marks the opening of the Milky Way's Dark Rift, seen universally in the past as an entrance to the sky-world.
Key words: Archaeoastronomy, Giulio Magli, Göbekli Tepe, Pre-Pottery Neolithic, Sirius, Cygnus, Orion, Hallan Çemi, Upper Paleolithic, liminal activities, polar stellar tradition, Milky Way, Dark Rift.
*Author of From the Ashes of Angels (1996), The Cygnus Mystery (2006) and Göbekli Tepe: Genesis of the Gods, upcoming 2014. **Chartered engineer MIET.
types of structure are seen, one evolving from the other. The earliest enclosures,
built most probably c. 9500-9000 BC, are composed of twin monoliths with T-shaped
terminations, which have been set up parallel to each other. Around them are circles,
or more correctly ellipses, of slightly smaller, radially positioned standing
stones, which are also T-shaped in appearance. These are placed in stonewalls,
often with stone benches between them.
though the sheer variety of enclosures present at Göbekli Tepe prevents a
single solution to their overall purpose and function, the parallel alignment
of the twin central monoliths has prompted speculation regarding their alignment
to celestial objects, a possibility the site's lead archaeologist Professor Klaus
Schmidt of the German Archaeological Institute (DAI) does not dismiss out of hand
(personal communication with Andrew Collins, September 2013).
archaeoastronomer Giulio Magli proposes that the twin central pillars in three
Gobekli enclosures-B, C, and D-targeted the rising of Sirius between the dates
9100-8250 BC (Magli, 2013). He points out that around 9300 BC Sirius began appearing
low on the south horizon having been invisible from the latitude of Göbekli
Tepe since c. 15,000 BC. The sight of this new "guest" star perhaps
motivated the Proto-Neolithic peoples of southeast Turkey to create Göbekli
biggest drawback with Sirius' use as a stellar target so soon after its reappearance
on the southern horizon is that it would have been barely visible, its usual bright
magnitude diminished greatly due to atmospheric extinction. A star's loss of brightness
is affected by many factors, including water vapour, dust particles and height
above sea level. Even in a clear sky with negligible pollution these effects can
be severe. In addition to this, atmospheric extinction causes a star's colour
to change. It becomes reddened and even less visible to the naked eye.
loss of brightness is measured by the apparent change of the star's magnitude.
Astronomical tables for average losses of brightness are given (Green, 1992).
Based on observations made at a height above sea level of 500m, a star at an altitude
of 5° loses 2.5 magnitudes. At an altitude of 1° it loses about 6 magnitudes,
and actually on the horizon it loses over 9 magnitudes.
has a magnitude of -1.46°, so at 5° altitude it becomes magnitude 1, which
is still bright. Yet at 1° altitude it becomes magnitude 4.5, which is extremely
dim. At 0.5° altitude, the height at which Magli proposes the Göbekli
builders targeted their monuments towards Sirius, the star possessed a magnitude
of 6, which is at the very limits of naked eye visibility. This would have been
the manner of its appearance for hundreds of years after its reemergence as early
as 9500 BC. Under any normal circumstances such an insignificant sight cannot
have moved an entire hunter-gathering culture to give up their old lifestyle and
start building the first monumental architecture in human history.
Fig.1. Sirius at half a degree altitude in 9100 BC showing its relative brightness to other stars (Credit: Stellarium).
problem is atmospheric refraction, which Magli makes no reference to in his paper.
He doesn't tell us whether it has or has not been taken into account, leaving
some doubt over his Sirius azimuth figures. When altitudes as low as half a degree
are employed for alignment purposes, refraction will raise the apparent altitude
of a star by around half a degree, necessitating an adjustment to any proposed
Until further details emerge this uncertainty must be borne in mind as we examine Magli's proposed mean azimuths for the twin central pillars of the enclosures involved, and the corresponding dates at which they target the rising of Sirius:
D 172° 9100 BC
only do these dates reflect the monuments' approximate epoch of construction,
but they also show very clearly that the twin pillars target a single star as
it gradually shifts its rising or setting position on the local horizon due to
the effects of precession (a point previously noted by both Schoch and the current
authors). This is caused by the slow wobble of the earth against the stellar background
across a cycle of nearly 26,000 years.
Frustratingly, Magli's mean azimuths for two of the enclosures differ from those suggested by the DAI's site plan. When all these factors are taken into account a slightly different correlation is revealed between the mean azimuths of the twin pillars and the rising of Sirius at a height of half a degree:
D 173° 9400 BC
As can be seen from these revised figures (and from Fig. 3), in two instances the correlation date between Sirius rising and the alignment of the pillars has been shifted back hundreds of years, even though this adds little to Magli's theory. For instance, in 9400 BC when the twin pillars of Enclosure D would have aligned with the rising of Sirius at half a degree (with refraction taken into account), the star would still have been barely visible to the naked eye as it crawled along the horizon (see Fig. 4).
8950 BC when Enclosure C's twin pillars targeted Sirius, the star would still
have been faint as it moved across the horizon. Yet here, in Enclosure C, there
is an added problem. The star would not have been seen from the position of the
twin central pillars, as a rocky slope to the south partially obscures the view.
Excavations in 2012 uncovered a staircase cut into the slope for use by entrants
approaching from the south (Dietrich, 2013).
8275 BC, when the central pillars of Enclosure B targeted the rising of Sirius,
the star climbed to make a much more appreciable arc, reaching a maximum elevation
of 6° as it crossed the meridian, due south. Despite this encouraging fact,
we now come into massive dating issues. Bone samples taken from Enclosure B have
provided radiocarbon dates in the range of 8306-8236 BC (Schmidt and Dietrich,
2010), around the same time that its twin pillars targeted Sirius at an altitude
of half a degree. Yet according to the excavators these human remains may well
derive from an intrusive burial made long after the structure's construction.
Indeed, since Enclosure B is built on the plateau's bedrock next to Enclosures
C and D, the chances are all three are roughly contemporaneous, meaning that Enclosure
B was most probably in existence by around 9000 BC. If so, then its twin central
pillars cannot have been built to target the rising of Sirius in 8250 BC.
might be proposed that instead of using an altitude of half a degree as the rising
of Sirius, why not use either 1° or, preferably, 2°, when the star would
have gained a slightly better magnitude. This could be done, although because
the star will have moved sufficiently by the time it reaches these greater magnitudes
it creates correlation dates much younger than those proposed here, perhaps by
as much as a thousand years. Then the same problems that caused Magli to discount
Orion as a stellar target at Göbekli Tepe would apply, for as he suggests,
it would mean "too low dating for the structures".
North not South
we examine Giulio Magli's premise, necessary for his theory, that Göbekli
Tepe's main enclosures are open to the south, enabling the light from Sirius to
enter their interiors in a manner found in connection with later megalithic monuments
overwhelming evidence to show that many megalithic structures were indeed designed
to allow the light of celestial objects to penetrate their interiors (Newgrange
in Ireland's Boyne Valley being the prime example), there is no reason to assume
the monuments of Göbekli Tepe, built several thousand years earlier, formed
part of this same tradition. Its curvilinear structures seem to represent a supersizing
of cult shrines that already existed throughout the Near East.
Enclosures A, B, C, D and E were all built on the mountain bedrock with uninterrupted views of the local horizon (although, as we have seen, Enclosure's C view of the southern horizon is at least partially obscured by a rising slope-see Fig. 5). In time these primary enclosures were decommissioned and covered over by a gradually emerging occupational mound or tell, constructed from imported soil, stone chippings, and general refuse including faunal remains and some human remains.
directional preference appears to have been adopted from existing cult shrines
of the Proto-Neolithic age. For instance, at Hallan Çemi, a site in the
Eastern Taurus Mountains of eastern Turkey, two circular buildings were uncovered,
dating to c. 10,250-9600 BC. Stone benches lined their interior walls, with hearths
at their centres (Rosenberg, 1999; Peasnall & Dyson, 2002).
It seems clear that this is a prototype of ritual structures that are to be found in more elaborate forms several hundred years later at Jerf el Ahmar (in northern Syria) and Mureybet (on the Middle Euphrates, also in Syria) in village contexts and perhaps even Çatal Höyük, where bucrania preferentially adorned the north walls (Hayden, 2003, 207).
Hayden infers, the north was the primary direction of orientation of Proto-Neolithic
and later Neolithic cult structures right down to the time of Çatal Höyük.
Since Hallan Çemi was almost certainly a precursor to Göbekli Tepe,
which lies some 225 km to the southwest, it very likely influenced the style and
design of the monuments there, including their northerly orientations.
the twin central pillars in the main enclosures at Göbekli Tepe are aligned
to a celestial object the chances are it was a near circumpolar star, i.e. one
that rose on the north-northeast horizon, arced over the celestial pole on its
upper transit, and then set on the north-northwestern horizon as it reached the
climax of its lower transit.
examination by the authors of the mean azimuths of the twin central pillars in
three enclosures-C, D and E-shows a precise correlation with Deneb, the brightest
star in the constellation of Cygnus in the epoch c. 9400-8900 BC. The star's setting
(not its rising as Magli states) on the north-northwestern horizon would have
been fully visible to the Pre-Pottery Neolithic peoples of Göbekli Tepe right
down to an altitude of 2°, when it would have finally faded from view.
Tepe's Pillar 43 in Enclosure D shows a vulture with wings articulated in a manner
that gives the bird the appearance of Cygnus (Vahradyane and Vahradyane, 2010
and see Fig. 6), while below it is a scorpion identified as a possible representation
of Scorpius (Belmonte, 2010).
Further confirmation of Enclosure D's alignment to Cygnus was the recent discovery immediately to the east of Pillar 43 of a large holed stone that stands erect within the north-northwestern section of the perimeter wall. In contrast to the radially aligned pillars in the various enclosures, this holed stone has its widest face facing towards the twin central pillars. Anyone standing or crouching between these huge monoliths in c. 9400 BC, the approximate date of construction of the enclosure according to available radiocarbon evidence (Schmidt and Dietrich, 2010), could have peered through this hole to watch the setting of Deneb (see Fig. 8). The fact that carved imagery on the holed stone might well represent an abstract female form, the opening as her vulva, expresses a symbolic act in which Deneb and the entrance to the Dark Rift are recognised as the direction of new life entering the enclosure's interior from the starry realms to the north.
Fig. 8. Plan of Enclosure D showing the position of Pillar 43 and the holed stone in the NNW section of the perimeter wall. The arrow indicates the setting of Deneb in 9400 BC (Credit: Rodney Hale).
later did the switch towards other directions occur, most obviously the east,
the direction of the rising sun. Enclosure F (not Enclosure E as Magli states)
has an azimuth of 59°, directing it towards sunrise at the time of the summer
solstice, while the Lion Pillar Building built on top of the tell, as much as
15m above the enclosures situated on the bedrock below, is orientated east-west.
Its eastern end-where twin pillars bearing carved reliefs of rearing lions are
to be seen-is almost certainly directed towards sunrise at the time of the equinoxes.
Its twin lions, which face into the room, are very likely symbols both of the
might of the sun, and arguably the presence of the constellation of Leo, the celestial
lion. This would have risen into the sky immediately prior to the sun at the time
of the spring equinox.
is clear that Sirius is unlikely to have been the primary focus of the earliest
enclosures at Göbekli Tepe, due to its faint appearance and feeble movement
during the epoch of their construction. Moreover, unless peoples from more southerly
climes introduced the Göbekli builders to its greater significance, Sirius
would have been seen as unimportant during the initial phase of construction at
the site. This severely weakens any claims that Göbekli Tepe's twin central
pillars were aligned to target the rising of this star.
J. A., "Finding Our Place in the Cosmos: The Role of Astronomy In Ancient
Cultures", Journal of Cosmology 9 (2010), 2052-62.