Related papers: Dating of a Latin astrolabe
Near the end of the 16th century Wilhelm IV, Landgraf von Hessen-Kassel, set up an observatory with the main goal to increase the accuracy of stellar positions primarily for use in astrology and for calendar purposes. A new star catalogue…
This paper presents a hands-on introduction to the medieval astrolabe, based around a working model which can be constructed from photocopies of the supplied figures. As well as describing how to assemble the model, I also provide a brief…
"El Cielo de Salamanca" ("The Sky of Salamanca") is a quarter-sphere-shaped vault 8.70 metres in diameter. It was painted sometime between 1480 and 1493 and shows five zodiacal constellations, three boreal and six austral. The Sun and…
Sunspot catalogs are very useful for studying the solar activity of the recent past. In this context, a catalog covering more than three solar cycles made by the astronomers of the Madrid Astronomical Observatory in Spain (nowadays, the…
We analyse a manuscript star catalogue by Wilhem IV, Landgraf von Hessen-Kassel, from 1586. From measurements of altitudes and of angles between stars, given in the catalogue, we find that the measurement accuracy averages 26 arcsec for…
The Caral civilization developed on the north-central coast of Peru and had an occupation period between 2870 and 1970 years BC. The first studies carried out in the field of archaeoastronomy showed evidence of possible astronomical…
This article advances the hypothesis that the heightened eschatological sensitivity evident among the historians writing in the 5th century and its weaker echos in the time of Charlemagne were caused by the irregularities of the the…
The use of the observed positions of celestial bodies to determine the location of a navigator and to direct vessels, was an aspiration of ancient seafarers. Various peoples, in the Mediterranean as much as in the Indian Ocean, in China as…
This paper presents an analysis of the star atlas included in the medieval Chinese manuscript (Or.8210/S.3326), discovered in 1907 by the archaeologist Aurel Stein at the Silk Road town of Dunhuang and now held in the British Library.…
As the European maritime powers expanded their reach beyond north Atlantic coastal waters to distant lands as far away as the East Indies, access to a practical means of maritime navigation in the southern hemisphere became imperative. The…
Astrometric calibration is based on patterns of cataloged stars and therefore effectively assumes a particular epoch, which can be substantially incorrect for historical images. With the known proper motions of stars we can "run back the…
The two main components of the closest star system, {\alpha}-Centauri AB(RA 14h39m, Dec-60o50', J2000.0) is indubitbaly one of the most studied visual double stars. This paper presents the results of our recalculation of orbital and…
This is a historian's view of how modern astronomy data can be used to discuss the shifting historical worldview of Late Antiquity. In this article an attemp is made to construct an approximate model of how the cycles of astronomical…
Armed with an astrolabe and Kepler's laws one can arrive at accurate estimates of the orbits of planets.
The solar program of the Astronomical Observatory of Madrid started in 1876. For ten solar cycles, observations were made in this institution to determine sunspot numbers and areas. The program was completed in 1986. The resulting data have…
Old algorithms are still in use nowadays setting the Easter date accordingly to some elements giving the Spring Equinox and the New Moon for a given year. At least two different approaches (by the Orthodox and Catholic Churches) provide…
The Clementine gnomon has been built in 1702 to measure the Earth's obliquity variation. For this reason the pinhole was located in the walls of Diocletian's times (305 a. D.) in order to remain stable along the centuries, but its original…
A re-investigation of the parapegma of Euktemon (5th century BC, Athens), based on the assumption that some star observations may in fact have been calculated rather than directly observed. The calculation follows Pliny, Natural History…
Previously, the most prominent explanation for the Star of Bethlehem was to identify one of many astronomical events in the sky as being the inspiration for the trip of the Magi. However, all the astronomical answers have detailed…
We present the results of determination of Pluto's positions derived from photographic plates taken in 1930 - 1960. Observations were made with Normal Astrograph at Pulkovo Observatory. Digitization of these plates was performed with high…