Rudolphine Tables and instructive examples for computing planetary positions. For most stars these tables were accurate to within one arc minute, and included corrective factors for atmospheric refraction. The tables were sufficiently accurate to predict a transit of Mercury observed by Pierre Gassendi in 1631 and a transit of Venus observed by Jeremiah Horrox in 1639. Rudolphine Tables The Rudolphine Tables () consist of a star catalogue and planetary tables published by Johannes Kepler in 1627, using some observational data collected by Tycho Brahe (1546–1601). The tables are named as "Rudolphine" in memory of Rudolf II, Holy Roman Emperor. Star tables had
Stellar triangulation Stellar triangulation Stellar triangulation is a method of geodesy which uses cosmic instead of terrestrial targets. It was first done by the Finnish geodesist Väisälä in 1959, who made astrometric photographs of the sky at two stations together with a balloon probe between them. Even this first step showed the potential of the method, because Väisälä got the azimuth between Helsinki and Turku (a distance of 150 km) with an accuracy of 1″. Soon the method was successfully tested by ballistic rockets and for some special satellites. Adequate computer programs were written for The advantage of stellar triangulation is the