Dama Ali as Astronomical Origin Point: The Sirius-Standstill Identity and the Siting of Lalibela

This revision restates the paper with every stellar quantity computed at its own epoch. The identity is presented as a function of time; the founding parallel is fixed by a different and epoch-specific coincidence; the pit-window material is reduced to a prediction for survey; and the combined-probability estimate of the first version, which included that material, is not restated. Any figure of the first version not restated here is not maintained. At a latitude φ where φ + |δ_Sirius| = ε + i, the zenith distance of Sirius at culmination equals the Moon’s maximum standstill declination. Because Sirius has a large proper motion, that latitude moves: it is undefined before the third millennium BCE, stands at 8° N in 2500 BCE, and only in the Common Era, with the star’s declination stationary near −16°, lies between 13° and 11.9° N. The identity is therefore a property of the last two thousand years, and it selects the parallel on which the highland kingdoms of Aksum and Lalibela stood: Lalibela (12.031° N) lies 0.75° from the identity latitude of its own century and 0.16° from today’s, and is the nearest site of sacred function to the modern identity parallel of 11.87° N. The founding of the tradition the author reconstructs is placed at the Dama Ali volcano (11.28° N) in the Afar about 15,500 BCE, and that placement is fixed here not by the identity but by an epoch-specific coincidence: in 15,510 BCE the Sun crossed the southern intersection of the Milky Way with the ecliptic, beside the Galactic Centre, at a declination of +11.14°, the island’s latitude to a tenth of a degree, so that the Sun entered the Milky Way at the island’s zenith on its spring day of no shadow, while the Northern Cross held the celestial pole and the Galactic Centre culminated 4.5° from the zenith. The coincidence holds within a day or two for some four centuries and dissolves outside them. The great-circle bearing from Bete Giyorgis to Dama Ali, 106.27°, coincides with the rising azimuth of Sirius at Lalibela for the whole of the Common Era, the star’s declination having been stationary at −15.9° from 260 BCE to 1550 CE; the church’s access trench is cut on that bearing. A closing section shows that the founding configuration recurs with the great year in its solar, galactic and polar elements but not in its stellar element: Sirius rose from the island at 142° at the founding, will rise at 145.5° at the next recurrence in the eleventh millennium CE and at 152° at the one after, and rose at 133° and 126° at the two before, so that the founding sky, taken whole, occurred once.