Date of Issue: 6 May 2009
Country: Czech Republic
Denominations: 17.0 Kč
The Association of European Public Postal Operators PostEurop declared "Astronomy" as this year's common theme for the postage stamp issue EUROPA. At the initiative of professional astronomers associated in the International Astronomical Union the year 2009 was proclaimed by the UNESCO as the International Year of Astronomy under the auspices of the UN. This event is closely related to the 400th anniversary of use of astronomical telescope by Galileo Galilei. At an international conference the Czech Republic will commemorate also the 400th anniversary of publication of a Kepler's major work Astronomia Nova.
The astronomer, mathematician, physicist and astrologer, Johannes Kepler (1571-1630), was a man of significance not only for the Czech environment. In 1600 he came to Prague already as a convinced follower of Koperník's system. At the emperor Rudolf II's court he became a colleague of Tycho Brahe and after the latter's death (1601) he took the position of the emperor's mathematician and astronomer. Kepler who was convinced of a harmonious structure of the world believed that the grouping of planets into specific geometrical figures has an extraordinary impact on the world events. On basis of data obtained by Brahe he calculated the elliptic orbit of the planet Mars and formulated the first two of his famous laws which regulate the motion of planets. The results were published in 1609 in his work Astronomia Nova. In 1612 Kepler left Prague for Linz where in 1618 he formulated his third law on planetary circulation. J. Kepler belongs to the major astronomers of the 17th century. He dealt with geometry, observed the explosion of a supernova, improved and constructed astronomical telescope. He as the first man actually calculated the so-called Bethlehem star. He found that it was the three-times repeated conjunction of Jupiter and Saturn in Pisces in 7 BC that was the "star of Bethlehem". Such unique phenomenon which as a matter of course could not escape general curiosity gave birth to the "comet".