Introduction

From the Vth millenium before our era dates the building of the very first megalithic monuments (menhirs, dolmens, cromlechs, ...). Most of these standing stones are characterized by a specific astronomical orientation : they were often built facing the rising or setting position of a bright celestial object (Sun, Moon, star, ...), indeed. It is the same for most of the later monuments dating from the mesopotamian, the egyptian, the mayan, the inca, ... periods.

This software leads to determine the astronomical source of orientation of any monument. It was conceived on the basis of the most recent algorithmic developments in Celestial Mechanics, Astrophysics and Optics. Since it takes into account the geographical (latitude, longitude and altitude of the site chosen for erection) and meteorological (temperature and relative humidity of the ambient air) conditions of observation, as well as the visual acuity of the stargazer, that is to say, our ability to distinguish a bright source in the background sky, this original software will give you results in quite good accordance with what was really observed at the epoch considered, that is to say, a list of stars visible with the naked eye whose sighting of the appearance or transit or disappearance position in the night or twilight sky explains the alignment of the monument considered. In some cases, the heliacal rising or setting of a star effectively was prefered to its rising or setting in the dark sky - mainly for worship reasons.

Fill in the form with the date of erection of the considered monument - between 4712 BC and 2017 AD -, with its azimuth of orientation and the latitude and altitude of the place chosen for observation as well as with the visual acuity of the observer. The software will then give you a list of stars of apparent magnitude smaller than 4 whose rising or transit or setting position was possibly used to align this monument. It will then be possible for you to deepen your search by determining the rising or transit or setting azimuth of every one of these stars in the dark sky and the twilight sky. Among the candidate stars, always favour the brightest ones ! You will then know with a great probability the star used to align the considered monument.

Access to the user interface

The price of this original astronomy software is 35 euros. This amount includes an unlimited access to the user interface and a free access to any future updates. To purchase this software by credit card or PayPal balance on the PayPal secure payment server, add it to your PayPal Cart. To do so, please click on the following logo :

Further Culture Diff' resources

Dossiers > AstroEgypto : The round Dendara zodiac. The temples of Isis and Hathor.
Dossiers > AstroEgypto : The astronomical orientation of the pyramids of Egypt
Dossiers > HistoSciences : Astronomie antique et moderne : d'observations en modélisations toujours plus poussées
Publications > Wiki AstroEgypto : Introduction aux méthodes de l'archéoastronomie. Seconde Partie : Application à la détermination de la source astronomique d'orientation d'édifices

Bibliography

Allen, C.W., "Astrophysical Quantities", Third Edition, Athlone, London, 1976.
Borkowski, K.M., "ELP 2000-85 and the Dynamical Time - Universal Time Relation", Astronomy and Astrophysics, 205 (1988), L8-L10.
Bower, F.A. et Ward, R.B., "Stratospheric Ozone and Man", CRC Press, Boca Raton, 1982
Bureau des Longitudes, "Introduction aux Ephémérides Astronomiques", EDP Sciences 1998.
Centre de Données Astronomiques de Strasbourg : http://cdsweb.u-strasbg.fr .
Chapront-Touzé, Michelle et Chapront, Jean, "Lunar Tables and Programs from 4000 BC to AD 8000", Willmann-Bell, Richmond, 1991, pp 6-7.
Garstang, R.H., "Night-Sky Brightness at Observatories and Sites", PASP101, 306-329, 1989.
Hayes, D.S., et Latham, D.W., "Rediscussion of the Atmospheric Extinction and the Absolute Spectral-Energy Distribution of Vega", Astrophysic Journal, 197, 593-601, 1975.
Hecht, S., "Visual thresholds of steady point sources of light in fields of brightness from dark to daylight", Journal of the Optical Society of America, 37, 59, 1947.
JPL Horizons : http://ssd.jpl.nasa.gov/horizons.html.
Koomen, M.J., Lock, C., Parker, D.M. , Scolnik, R., Tousey, R. et Hulburt, E.O., "Measurements of the Brightness of the Twilight Sky ", Journal of the Optical Society of America, 42, 353-356, 1952.
Krisciunas, K et al., "Atmospheric Extinction and Night-Sky Brightness at Maunea Kea", PASP 99, 887-894, 1987.
Krisciunas, K., "Further Measurements of Extinction and Sky Brightness on the Island of Hawaï", PASP 102, 1052-1063, 1990.
Krisciunas, K. et Schaefer, B. E., "A Model of the Brightness of Moonlight", PASP, 103, 1033-1039, 1991.
Meinel, A. et Meinel, M., "Sunsets, Twilights and Evening Skies", Cambridge University Press, Cambridge, 1983.
Pilachowski, C.A., Africano, J.L., Goodrich, B.D. et Binkert, W.S., "Sky Brightness at the Kitt Peak National Observatory", PASP 101, 707-712, 1989.
Pyaskovskaya-Fesenkova, E.V., "Investigations of the scattering of light in the earth's atmosphere", USSR Academy, Science Press, Moscow, 1957.
Rozenberg, G.V., "Twilight", Plenum, New York, 1986
Saemundson, T., "Atmospheric Refraction", Sky & Telescope, 72, 70, 1986.
Schaefer, Bradley E., "Atmospheric Extinction Effects on Stellar Alignments", Archaeoastronomy n°10 (JHA, xvii (1986)).
Schaefer, Bradley E., "Telescopic Limiting Magnitudes", PASP 102, 212-229, 1990
Schaefer, Bradley E., "Astronomy and the limits of vision", Vistas in Astronomy, Volume 36, pp 311-361, 1993.
Schaefer, Bradley E., "The latitude of the observer of the Almagest star catalogue", JHA xxxii, 2001.
Simon, J.L., Bretagnon, P., Chapront, J., Chapront-Touzé, M., Francou, G., Laskar, J., "Numerical expressions for precession formulae and mean elements for the Moon and the planets", Astronomy Astrophysics 282, 663-683 (1994).
Stephenson, F.R., "Historical Eclipses and Earth Rotation", Cambridge University Press, Cambridge, 1997.
Stephenson, F.R. et Morrison, L.V., "Long-Term Fluctuations in the Earth's Rotation : 700 BC to AD 1990", Philosophical Transactions of the Royal Society of London, Ser. A, 351 (1995), 165-202.
Stephenson, F.R. et Morrison, L.V., "Long-Term Changes in the Rotation of the Earth : 700 BC to AD 1980", Philosophical Transactions of the Royal Society of London, Ser. A, 313 (1984), 47-70.
Tousey, R. et Hulburt, E.O., "Visibility of Stars in the Daylight Sky", Journal of the Optical Society of America, 38, 886-896, 1948.
Weaver, H.F., "Visibility of Stars Without Optical Aid", PASP 59, 232-243, 1947.