Astronomical Images : Astronomical sextant

Tycho Brahe

Astronomical Images

<p style='text-align: justify;'>Having lost the favour of the Danish court in the latter years of the sixteenth century, Tycho Brahe published his <i>Astronomiae instauratae mechanica</i> in 1598 as part of a strategy to procure royal patronage elsewhere. Addressed to his eventual patron, Holy Roman Emperor Rudolph II, the work lavishly described and illustrated the innovative astronomical instruments that Tycho had designed and constructed on the island of Hven, the site of his astronomical programme under the patronage of the Danish court. Though primarily focused on his instruments, the work also included an appendix on 'architectonic structures suitable for astronomical observations', which offered descriptions and illustrations of his two observatory buildings, as well as a map of Hven based on his own observational data. As such, the <i>Mechanica</i> offered not simply an overview of Tycho's instruments, but rather a presentation of his whole astronomical programme for which he was seeking financial support. This image presents one of Tycho's sextants, an instrument that the astronomer claims to have invented. It could be used to measure either celestial altitudes or angular distances; here, it is positioned for the measurement of altitudes. In the description of this instrument, Tycho takes pains to emphasise his priority regarding its invention, despite others claiming it as their own. He also emphasises that this sextant was constructed in such a way as to enable it to be easily taken apart and reassembled, to facilitate transportation. This not only reflects Tycho's ambition for a 'universal astronomy', but perhaps his more salient concern at this time of finding a new patron, emphasising a capacity for relocation. As Tycho himself declares, 'An astronomer ... has to be a citizen of the World, and consider every place to which circumstances or necessity might lead him as his homeland.'</p>