MONOGRAPHS

Gaia

"Charting the Galaxy – from Hipparcos to Gaia” In this vodcast Rebecca Barnes discovers the motions of the stars, learns how astronomers measure their distances and looks at the new European mission that will really get to grips with our place in the Universe: Gaia.

The star of Bethlehem

Detailed analysis, based on the investigations done by the astrophysicist Mark R. Kidger, on the astronomical phenomena which, due to its nature and chronology, are good candidates to have caused the strange appearance of the very bright star which drove the Three Wise Men to the birthplace of the Messiah, as is explained in the Gospel.

Calculation of the distance between the Earth and the Sun from observations done during a transit of Venus.

Through the main part of the history of modern astronomy, the observations carried out during the transits of Venus, one of the most extraordinary events of astronomy, were the best method to measure the distance to the Sun. That is the reason why western countries undertook expensive expeditions in order to make the appropriate observations. In this article, one of the methods to carry out this calculation is explained. Necessary simplifications have been added so that not specialized readers could understand. Nevertheless, basic knowledge on geometry and trigonometry are needed.

The history of transits

Article on how the planetary transits were discovered and how astronomers have been obtaining information from them through these last centuries.

The Christian (or Western) Calendar

Not available in English (only in Spanish and Catalan).
Article on the evolution of the calendar we use nowadays in the Western World, the Gregorian Calendar. A complete history from the first solar calendar we know, the Egiptian calendar, to the one we use is made, putting special attention on the important reform introduced by the Julian Calendar.