Hevelius’s depiction of Scutum
Scutum as shown by Johannes Hevelius in his Firmamentum Sobiescianum star atlas published in 1690. Here, the name of the constellation is abbreviated from Scutum Sobiescianum to Scutum Sobiescian. Hevelius decorated the shield with a shining cross in recognition of the fact that King John Sobieski and his forces helped repulse the Turkish siege of Vienna, the capital of the Holy Roman Empire, in 1683. Hevelius gave a long and gushing description of the King’s exploits in the Introduction to his catalogue and atlas called Prodromus Astronomiae.
Scutum was constructed from seven stars of 4th and 5th magnitudes, three around the central cross and four others around the rim of the shield; the southernmost of these Hevelius described as ‘nebulous’ but it is in fact a double star (the present-day Gamma Scuti). None of these stars had been catalogued by Ptolemy, and this area was blank on early charts such as Dürer’s hemispheres of 1515. In his original manuscript Hevelius had intended these seven stars to form the lower half of Antinous, to the right on this chart, before deciding in 1684 that they would be better used to honour the king. Presumably the king never discovered that his new constellation was originally meant to have been the feet of a Roman emperor’s catamite.
Like all constellations in Hevelius’s atlas it is shown in mirror image, as on a celestial globe. However, his initial diagram announcing the constellation, published in the scientific journal Acta Eruditorum in 1684, showed it the right way round, as seen from Earth. Confusingly, the diagram of Scutum was published alongside that of another new and unrelated constellation, Gladii Electorales Saxonici (Swords of the Electors of Saxony), invented by the German astronomer Gottfried Kirch, which was soon forgotten.
Image courtesy ETH-Bibliothek Zurich.
