Facebook

Zach, Franz Xaver von (1754–1832)

Hungarian astronomer, surveyor, teacher, scientific journal founder, observatory director, member of several scientific academies. Excellent organizational abilities, highly respected man who was what we now would call manager. Played a significant role in the discovery of asteroids.

Franz Xaver von Zach (1754–1832) can not be found on commemorative medal. The only medal that mentions his name is what he ordered along with his friend Bernhard von Lindenau in honor of their common friend Heinrich Wilhelm Olbers, a medical doctor.

The foundation of astronomical association in Lilienthal

Enforced by the success of astronomical meeting Zach and his German astronomer friends initiated to establish an astronomical association. For the founding conference Schröter's observatory in Lilienthal was chosen. The meeting took place between 13-20, September 1800. The association founders were: Ferdinand Adolf von Ende, Johann Gildemeister, dr. Heinrich Wilhelm Matthias Olbers, Karl Ludwig Harding, von Zách and Johann Hieronymus Schröter.
The participants intended their association to be international, and by common accord the next astronomers were invited to be a member:
Johann Elert Bode, Berlin; Joseph Tobias Bürg, Wien; Thomas Bugge, Copenhagen; J. C. Burckhardt, Paris; Wilhelm Herschel, Slough, Windsor; Prof. Hurth, Frankfurt am Oder; Georg Simon Klügel, Halle; dr. Koch, Danzig; Nevil Maskelyne, Greenwich; Prof. Melanderhjelm, Stockholm; Pierre Méchain, Paris; Barnaba Oriani, Milan; Joseph Piazzi, Palermo; Schubert, Saint Petersburg; Prof. Sniadecki, Krakko; Charles Thulis, Marseille; Johann Friedrich Wurm, Blaubeuren; Ferdinand von Ende, Celle; Johann Gildemeister, Bremen; Karl Ludwig Harding, Lilienthal; Prof. Svanberg, Uppsala; Wilhelm Olbers, Bremen; Johann Hieronymus Schröter, Lilienthal; von Zách, Gotha.
The listed names can be found among the authors of AGE and its successor the Monatliche Correspondenz, published since January 1, 1800.

The newly formed astronomical association aimed the following tasks:

  • full exploration of the sky between the planets Mars and Jupiter to find previously supposed unknown planet;
  • to search for comets only visible in telescopes, quickly identify of track parameters and to make them available to other researchers;
  • determination of the parallax of fixed stars;
  • search for variable stars;
  • In order to prepare a better than ever star chart introduce astronomers' work with their peers and establish a working relationship among them using the Monatliche Correspondenz.

Vargha Domokosné : Zách János Ferenc (1754–1832) Csillagász, Hungarian

Olbers also gained prestige among professional astronomers with his astronomical observations. Thanks to this, Baron Franz Xaver von Zach and his German astronomer friends invited him into their newly formed astronomy association. On the foundation of Celestial Police (Himmelspolizei as the founders called themselves), see sidebox.

The Association has reached its goal, and although the first asteroid, Ceres was found accidentally by the Italian astronomer Piazzi, the second and fourth by Olbers, thanks to the systematic search. The international astronomer organization was ahead of its time, and though it was broken up in 1815 in the belief that no more asteroid to be discovered, the members remained in friendly connections with each other. Probably due to this friendship that Olbers – in addition to the above, the "official" medallion – from his close friends also received a commemorative medal for 50th anniversary of his doctorate.

On the obverse of the 50mm diameter and 69 grams weight bronze medal are two griffins holding in their beaks a decorative wreath above it portraits of Pallas Athena and Vesta (or Greek name Hestia), the goddess of the family and the home, and above them one-one star. Below them dates by Roman numerals, on the left side the discovery of asteroid Pallas (28 March 1802), on the right side of Vesta (29 March 1807) were displayed.

olbers-zach 1830 obverseolbers-zach 1830 reverse

The mischievous eight-line legend on the reverse of the medal reflects this friendly relationship too. "GVILELMO OLBERS / PALLADIS ET VESTAE SACERDOTI / SAEMISSAECVLARES / DOCTORIS HONORES / GRATVLANTVR SODALES / ZACH · LINDENAU· / DIEM XXVIII · M · DECBR· / MDCCCXXX", i. e. for Guilelmo Olbers, priest of Pallas and Vesta, in honor of half century of his doctorate  congratulate his mates Zach (and) Lindenau on 28th day of the month December, 1830.