(b. ca. 1696; d. Berlin, 6 May 1782), astronomy.
Gottfried Kirch was the son of a tailor. Because of the unrest of the times, his parents were forced to flee to Poland; on the way, the enemy took all their belongings, and apparently Gottried had to provide for himself while continuing his education. He studied at Jena under the then famous polyhistorian Erhard Weigel, who recommended him to Hevelius in Danzig, one of the most careful observers of his time. After his apprenticeship Kirch returned to Guben, but he also lived for periods of time in Leipzig and Coburg.
In 1692 he married Maria Margarethe Winkelmann (apparently his second wife), the daughter of a Protestant minister. It is thought that she had become interested in astronomy through Christoph Arnold of Sommerfeld, the so-called “astronomical peasant.” Arnold was a self-taught astronomer from near Leipzig who observed, among other astronomical phenomena, the great comet of 1683 and the transit of Mercury in 1690. The council of Leipzig was so impressed with these accomplishments that they gave him a sum of money and lifelong freedom from taxes. After his death in 1697 his picture was placed in the library of the city council. Arnold willed part of his manuscripts to Kirch and the rest to the library of the Leipzig city council.
Kirch had fourteen children, two of whom became astronomers. He made his living by computing and publishing calenders and ephemerides. His first calendar appeared in 1667 in Jena and Helmstedt. Calendars were published yearly from 1685 until 1728 in Nuremberg; after Gottfried’s death in 1710 his son Christfried continued to publish them under his father’s name. The calendars were made with care and became very popular. His ephemerides were calculated for the years 1681-1702. They were based essentially on Kepler’s Rudolphine tables and were well-known throughout Europe. Kirch was the first to introduce Halley’s Catalogus stellarum Australium (1679) to Germany by publishing it as a supplement to his ephemerides for 1681. He was one of the earliest astronomers to search the skies systematically with a telescope and thus discovered several comets, among them the large one of 1680. This comet became an important link in cometary theory, and on the basis of observations of it, Newton indicated the method which Halley used to calculate the parabolic orbits of twenty-four comets.
In 1638 Holwarda of Franeker had found that the magnitude of a star in Cetus fluctuated with a periodicity of 11 months; it was named Mira Ceti (“the miraculous one in the Whale”). In 1667 Montanari at Bologna noticed variations in Algol, and in 1672, a variable star in the constellation Hydra. Kirch had also described Mira Ceti in 1678, and in 1685 he discovered a variable star in the neck of the constellation Cygnus (“in collo Cygni”). He calculated that it had a periodicity of 404½; days. Kirch also observed sunspots, eclipses, and the transit of Mercury in 1707, and designed a new, circular micrometer.
The acceptance of the Gregorian calendar by the Protestant estates of Germany at the end of the seventeenth century gave Frederick III, elector of Brandenburg (later Frederick I of Prussia), the impetus to found an astronomical observatory as well as an academy of science. Kirch was called to Berlin in May 1700 as the first astronomer. The official date of the founding was 11 July 1700, the king’s birthday. Because of the meager allotment of funds by the spendthrift king, the building, which was designed to house the observatory as well as the offices of the academicians, proceeded slowly, and the official ceremonies dedicating the building were not held until 19 January 1711, half a year after Kirch’s death. While waiting for the building to be finished, Kirch made his observations in his own house and in the private observatory in his own house and in the private observatory of Baron von krosigk. A wealthy nobleman and amateur astronomer, Krosigk. A wealthy nobleman and amateur astronomer, Krosigk sent his secretary Kolbe to the Cape of Good Hope in 1705 to make observations corresponding to those being made by Kirch in his observatory in Berlin.
Apparently Kirch had a rather phlegmatic, not too cheerful character and a sickly constitution. While living in Leipzig under difficult financial circumstances, some of his friends, without his knowledge, obtained a stipend from the elector; when Kirch heard about it, he refused to accept it for fear that some poor students, for whom the funds available for scholarship had originally been intended, would be deprived.
Kirch’s wife, Maria Margarethe, worked regularly with her husband making observations and especially doing calculations for calendars. After his death she continued to publish on her own. She discovered the comet of 1702, and in 1709 she published a pamphlet about the 1712 conjunction of the sun with Saturn and Venus. In 1712 she wrote about the coming conjunction of Saturn and Jupiter and also communicated rather extensive astrological prognostications, although she admitted that no great value should be given to her interpretation. She went to work in Krosigk’s well-equipped observatory in 1712, and upon his death in 1714 moved to Danzig. Peter the Great wanted her to come to Russia, but when her son Christfried became the astronomer of the Berlin observatory she joined him there. She continued to calculated calenders for Breslau, Nuremberg, Dresden, and Hungary until her death in 1720.
Christfried Kirch started his astronomical studies in Leipzig and then journeyed to Königsberg and Danzig to work in Hevelius’ old observatory. He put in order the manuscripts Hevelius had left behind and repaired his instruments so that they could be used for his own observations. He remained in Danzig for eighteen months; he returned to Berlin in 1716 to succeed J. H. Hoffman as astronomer of the Berlin observatory; this was the same position his father had held, and Christfried occupied it until his death in 1740. He was a careful observer who noted eclipses of the moon, occultations, and the transit of Mercury in 1720. By observing the eclipses of the satellites of Jupiter, he tried to calculate the differences between the meridians of Berlin, St. Petersburg, and Paris. Together with his assistant Grischon and the famous astronomer Celsius, he observed the solar eclipse of May 1733. He was also interested in ancient astronomical observations, especially those made in China, and Eastern calendars and chronologies. The French Academy of Sciences elected him as a regular correspondent in 1723, and he maintained an extensive correspondence with most of the European astronomers. Christfried was a hardworking, serious man who never married; he lived with his three sisters in complete harmony for almost twenty years. He died of a heart attack.
Christine Kirch assisted her brother Christfried with his observations and calculations. For many years she calculated the calender for Silesia.
I. Original Works. According to Lalande, Bibliographie astronomiques, J. de l’Isle acquired manuscripts and correspondence from the Kirch family for his collection of astronomical material. This collection was bought by the French government and placed in the Dépôt de la Marine. The Berlin Observatory also has manuscript observations. Aside form the ephemerides and calendars, most of their articles were published in Miscellanea berolinensia,1-5 (Berlin, 1710-1737). See Poggendorff I for complete listing.
II. Secondary Literature. See J. E. Bode, Astronomishes Jahrbuch für das Jahr 1816 (Berlin, 1813); and Allegemeine deutsche Biographie, XV, 787-788.
Lettie S. Multhauf