Tycho Brahe days days in the year pregnant with misfortune, wherefore in Denmark, up to this very day, the laboring class call such days on which they happen to meet with some unfortunate accident, Tycho Brahe's days." In his travelogue "A Poet's Bazaar", Hans Christian Andersen alludes to the fact that Tycho Brahe died in exile in Prague, observing that "Denmark owns not even his dust; but the Danes mention his name in their bad times, as if a denunciation proceeded out of it: 'These are Tycho Brahe's days!' say they." However, no mention of the Tycho Brahe days is actually found in
Tycho Brahe current observational data was a day off. He realized that more accurate observations would be the key to making more exact predictions. He purchased an ephemeris and books on astronomy, including Johannes de Sacrobosco's "De sphaera mundi", Petrus Apianus's "Cosmographia seu descriptio totius orbis" and Regiomontanus's "De triangulis omnimodis". Jørgen Thygesen Brahe, however, wanted Tycho to educate himself in order to become a civil servant, and sent him on a study tour of Europe in early 1562. 15-year old Tycho was given as mentor the 19-year-old Anders Sørensen Vedel, whom he eventually talked into allowing the pursuit of astronomy during