Christoph Arnold (astronomer)

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Christoph Arnold, oil painting by Johann Heinrich at the end
Epitaph for Christoph Arnold in the Sommerfeld Church

Christoph Arnold (born December 17, 1650 in Sommerfeld near Leipzig ; † April 15, 1695 ibid) was a German farmer and astronomer or, as his pastor put it on the epitaph, arable farmer and star gazer (Agricola Coelicola). He is described as a farmer and astronomical expert on the plaque on his house.

Life

Christoph Arnold was born as the eldest son of the farmer and judge Hans Arnold (1620–1685) from Sommerfeld and his wife Sabine. Hainmann (1621–1675) was born in Albrechtshain . Since he had to help out on his father's farm, he only went to school briefly. He was quick to grasp and it is believed that he had private lessons from his godfather Bartholomäus Sturm, schoolmaster in Panitzsch . Then he continued his self-taught education.

He was particularly interested in astronomy . He acquired astronomical knowledge in self-study and from the astronomer Gottfried Kirch (1639–1710), who was eleven years his senior , who worked without ties to an observatory in Guben , Lobenstein , Coburg and Leipzig. Arnold built a small, simple observatory on his father's house . He was particularly interested in comets , probably also stimulated by the appearance of the Great Comet of 1680 , which could be seen particularly brightly and even during the day, which caused a general sensation. Gottfried Kirch discovered him in Coburg. When Kirch moved to Leipzig in 1686, Arnold was one of his friends. Both undertook joint astronomical observations. At Arnold's, Kirch also met his second wife Maria Margaretha Winkelmann (1670–1720), whom Arnold had enthusiastic about astronomy.

On May 15, 1683, Christoph Arnold married Anna Straube from Sommerfeld. The couple had five children. His father died in 1685, and Christoph Arnold took over his father's farm, which he continued to run in an exemplary manner until the end of his life, despite his astronomical activities. He began with statistics about the crop yield, for which he also measured and recorded his fields. In the end he did that for the whole village. This makes him one of the first cartographers in Saxony. Arnold also observed the weather very closely and kept records. In 1692 he described a rare natural phenomenon: five simultaneous suns .

Arnold always went against superstitious beliefs and fear associated with the comets. Although he was a devout Christian, he did the same against his pastor, who presented comets as ominous signs.

His observatory was left as a memorial after his death, but had to be demolished in 1794 because of dilapidation.

Astronomical Achievements

On August 15, 1682, Christoph Arnold discovered a comet, eight days before the important astronomer Johannes Hevelius , with which the amateur astronomer attracted a great deal of attention in the professional world. The comet was later named Halley's Comet because of the precise orbital calculations by Edmond Halley and the prediction of its return . Arnold described his observations to the Leipzig council in a detailed document.

On September 16, 1686, Arnold was the first in Europe to see another comet ( C / 1686 R1 ), which he then continued to observe together with Gottfried Kirch. He published the results in the first general German scholarly journal Acta Eruditorum, which was published in Leipzig in 1682 .

Arnold also dealt with the double star Mira, which changes its brightness . Another area of ​​work was the eclipse of the four large moons of Jupiter , whose entry times he calculated in advance.

On October 31, 1690, he observed the passage of Mercury in front of the solar disk by projecting the sun through his telescope onto a sheet of paper. This was the fifth description of the passage of Mercury in Europe.

Honors

Memorial plaque on the house where he was born and where he lived

Arnold received high recognition for his services during his lifetime, but also afterwards.

In order to observe the passage of Mercury in front of the sun disk, he received a gift of money and exemption from taxes for life from the Leipzig council, because Sommerfeld, as the council village of Leipzig, was obliged to pay taxes there. In addition, the council had the painter Johann Heinrich make an oil painting by Christoph Arnold, the original of which is in the City History Museum in Leipzig and a copy hangs in the Sommerfeld Church.

In 1890, Arnoldstrasse was named after him in the then still independent village and today's Leipzig district of Stötteritz. His former farm is located on Arnoldplatz in the place where he was born and lived in Sommerfeld.

Astronomical objects have Arnold's name. Arnold crater near the north pole of the moon was named after him in 1935. On January 18, 1999, the asteroid with the provisional designation 1999 BW3 was discovered in the Drebach (Ore Mountains) public observatory. Since 2012 he has been remembering the Sommerfeld astronomer as (121016) Christopharnold . It moves around the sun between the planets Mars and Jupiter .

The elementary school in Engelsdorf , the district of which was Sommerfeld from 1923 to 1999, has been called the Christoph Arnold School since 1990.

literature

Web links

Individual evidence

  1. ↑ Title of the text: Divine signs of grace presented in a sun miracle. Leipzig 1692
  2. ↑ General German Real Encyclopedia for the Educated Estates , Volume 1, FA Brockhaus Verlag Leipzig 1833, p. 417 (digital)
  3. ↑ The title of this book was: Simple concern about the Comet recently seen in August of this 1682th year, Darinnen Of whose origin and cause of their tails, whose length, short and crooked is dealt with slowly and unpredictably, described by simple-minded farmers at Sommerfelt bey Leipzigk. (after Helfricht, p. 24)
  4. ^ Sebastian Kühn: Knowledge, Work, Friendship: Economics and Social Relations at the Academies in London, Paris and Berlin around 1700 . V&R Unipress 2011, ISBN 978-3-89971-836-2 , pp. 227/228
  5. ↑ JPL Small-Body Database Browser
  6. ^ Christoph-Arnold-Schule - primary school of the city of Leipzig. Retrieved June 6, 2017 .
personal data
SURNAME Arnold, Christoph
BRIEF DESCRIPTION German astronomer
DATE OF BIRTH December 17, 1650
PLACE OF BIRTH Summer field
DATE OF DEATH April 15, 1695
Place of death Summer field