Kirch’s Sceptrum Brandenburgicum and Pomum Imperiale




Obsolete constellations Pomum Imperiale and Sceptrum Brandenburgicum
Obsolete constellations Pomum Imperiale and Sceptrum Brandenburgicum

Gottfried Kirch’s illustrations of the obsolete constellations Pomum Imperiale and Sceptrum Brandenburgicum, representing an imperial orb and sceptre, published in the 1688 August edition of the scientific journal Acta Eruditorum. In the illustration at left, Antinous (also now obsolete) reaches out towards the Orb, while in the right half of the diagram the Sceptre straddles a meander in Eridanus, the river. On this engraving, the second letter ‘n’ in ‘Brandeburgicum’ is missing. Click for enlargements.




In 1688 the German astronomer Gottfried Kirch (1639–1710) published suggestions for two new constellations in the leading scientific journal of the day, Acta Eruditorum, as illustrated above. The first, which he titled Pomum Imperiale, the imperial orb, lay on the border between Aquarius and Aquila and was a blatant piece of flattery aimed at Leopold I, the Holy Roman Emperor at the time. Kirch placed the orb on the right hand of Antinous (itself now obsolete) and lettered its seven stars so they spelled out the name ‘Leopuld’. It was universally ignored.

Kirch’s second suggestion, Sceptrum Brandenburgicum (mis-spelled ‘Brandeburgicum’ on the diagram, i.e. with a missing letter n), fared somewhat better. This invention consisted of a nearly north–south line of five faint stars tucked into a bend of the river Eridanus next to Lepus, and was most likely intended to flatter Frederick III, the Elector of Brandenburg, a state of Germany which included Berlin.

Although initially ignored, it was later revived by the Berlin astronomer Johann Bode who depicted it on his atlases of 1782 and 1801. Eventually it joined the ranks of the celestial discards, but for Kirch the move paid off. In 1700 Fredrick III appointed him astronomer to the newly formed Brandenburg Society of Sciences (now the Berlin-Brandenburg Academy of Sciences and Humanities) and first director of its Berlin observatory, although he died before the building was officially opened.


Gladii Electorales Saxonici

Kirch had made a previous attempt to leave his mark among the constellations, also without success. In 1684 he published this illustration of a figure he called Gladii Electorales Saxonici in the area where Virgo meets Serpens Caput. 

It represented two crossed swords, part of the coat of arms of the Elector of Saxony, the German state in which he then lived. Kirch lettered its stars to spell out the name Johan Georg in honour of Johan Georg III who was Elector of Saxony at the time. (The letter o, where the swords cross, was used twice.) Kirch published this invention in the same edition of Acta Eruditorum as Hevelius’s Scutum Sobiescianum first appeared. Confusingly, the two diagrams were published side-by-side even though they were unrelated. Kirch worked for a while with Hevelius and probably got the idea of creating a constellation to flatter a patron from him.





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Gottfried Kirch’s constellation Gladii Electorales Saxonici, published in the 1684 August edition of the scientific journal Acta Eruditorum. Its brightest star, marked by the letter o where the swords cross, was the present-day 109 Virginis, magnitude 3.7.The constellation is drawn as though seen on a globe, so Johan’s name would have read backwards in the sky. Kirch did not make the same mistake with his later inventions, above.

Kirch's constellation Gladii Electorales Saxonici