Johannes-kepler-tabulae-rudolphinae-google-arts-culture

The ''Rudolphine Tables'' ( la, Tabulae Rudolphinae) consist of a

star catalogue A star catalogue is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, ...

and planetary tables published by

Johannes Kepler Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws ...

in 1627, using observational data collected by

Tycho Brahe Tycho Brahe ( ; born Tyge Ottesen Brahe; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was k ...

(1546–1601). The tables are named in memory of

Rudolf II, Holy Roman Emperor Rudolf II (18 July 1552 – 20 January 1612) was Holy Roman Emperor (1576–1612), King of Hungary and Croatia (as Rudolf I, 1572–1608), King of Bohemia (1575–1608/1611) and Archduke of Austria (1576–1608). He was a member of the Hous ...

, in whose employ Brahe and Kepler had begun work on the tables. The main purpose of the Rudolphine tables was to allow the computation of the positions of the then known

planets A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young ...

of the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

, and they were considerably more precise than earlier such tables.

Previous tables

Star tables had been produced for many centuries and were used to establish the position of the planets relative to the fixed stars (particularly the twelve constellations used in

astrology Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of Celestial o ...

) on a specific date in order to construct horoscopes. Until the end of the 16th century, the most widely used had been the '' Alphonsine tables'', first produced in the 13th century and regularly updated thereafter. These were based on a

Ptolemaic Ptolemaic is the adjective formed from the name Ptolemy, and may refer to: Pertaining to the Ptolemaic dynasty * Ptolemaic dynasty, the Macedonian Greek dynasty that ruled Egypt founded in 305 BC by Ptolemy I Soter * Ptolemaic Kingdom Pertaining ...

geocentric model In astronomy, the geocentric model (also known as geocentrism, often exemplified specifically by the Ptolemaic system) is a superseded description of the Universe with Earth at the center. Under most geocentric models, the Sun, Moon, stars, an ...

of the

. Although the Alphonsine tables were not very accurate, nothing else was available and so they continued to be used. In 1551, following the publication of ''

De revolutionibus orbium coelestium ''De revolutionibus orbium coelestium'' (English translation: ''On the Revolutions of the Heavenly Spheres'') is the seminal work on the heliocentric theory of the astronomer Nicolaus Copernicus (1473–1543) of the Polish Renaissance. The book, ...

'' by

Nicholas Copernicus Nicolaus Copernicus (; pl, Mikołaj Kopernik; gml, Niklas Koppernigk, german: Nikolaus Kopernikus; 19 February 1473 – 24 May 1543) was a Renaissance polymath, active as a mathematician, astronomer, and Catholic canon, who formulated ...

Erasmus Reinhold Erasmus Reinhold (22 October 1511 – 19 February 1553) was a German astronomer and mathematician, considered to be the most influential astronomical pedagogue of his generation. He was born and died in Saalfeld, Saxony. He was educated, und ...

produced the ''

Prutenic Tables The ''Prutenic Tables'' ( la, Tabulae prutenicae from ''Prutenia'' meaning "Prussia", german: Prutenische oder Preußische Tafeln), were an ephemeris (astronomical tables) by the astronomer Erasmus Reinhold published in 1551 (reprinted in 1562, 1 ...

'' based on a

heliocentric Heliocentrism (also known as the Heliocentric model) is the astronomical model in which the Earth and planets revolve around the Sun at the center of the universe. Historically, heliocentrism was opposed to geocentrism, which placed the Earth at ...

model of the Solar System, but these were no more accurate than the earlier tables. 8107-2Keplertp

Observations and prelude

The observations underlying the Rudolphine tables were performed by Tycho Brahe and his team. Brahe's measurements were much more accurate than the ones available previously. He worked with elaborate instruments to determine the precise positions of planets and stars in the sky but did not have a telescope. Brahe had been supported by the Danish king Frederick II and had built an observatory on the island of

Hven Ven ( da, Hven, older Swedish spelling Hven) is a small Swedish island in the Øresund strait, between Scania and Zealand (Denmark). It is part of Landskrona Municipality, Scania County. The island has 371 inhabitants and an area of . During th ...

during 1576–1596. When the king died, Brahe moved to

Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate ...

and became the official imperial astronomer of Emperor

Rudolf II Rudolf II (18 July 1552 – 20 January 1612) was Holy Roman Emperor (1576–1612), King of Hungary and Kingdom of Croatia (Habsburg), Croatia (as Rudolf I, 1572–1608), King of Bohemia (1575–1608/1611) and Archduke of Austria (1576–160 ...

. There he was joined by Kepler in 1600, and Rudolf instructed them to publish the tables. While Tycho Brahe favored a geo-heliocentric model of the solar system in which the Sun and Moon revolve around the Earth and the planets revolve around the Sun, Kepler argued for a Copernican

heliocentric model Heliocentrism (also known as the Heliocentric model) is the astronomical model in which the Earth and planets revolve around the Sun at the center of the universe. Historically, heliocentrism was opposed to geocentrism, which placed the Earth at ...

. When Tycho Brahe died in 1601, Kepler became the official imperial mathematician. By studying Brahe's data, he found his three laws of planetary motion, which he published in 1609 and 1619. Emperor Rudolf died in 1612 and Kepler left Prague.

Composition and publication

The tables were anticipated for many years, with pleas for its publication reaching as far as

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

and

Jesuit missionaries in China , image = Ihs-logo.svg , image_size = 175px , caption = ChristogramOfficial seal of the Jesuits , abbreviation = SJ , nickname = Jesuits , formation = , founders = ...

. Apart from external hindrances, Kepler himself refrained from such a monumental enterprise involving endless tedious calculations. He wrote in a letter to a Venetian correspondent, impatiently inquiring after the tables: "I beseech thee, my friends, do not sentence me entirely to the treadmill of mathematical computations, and leave me time for philosophical speculations which are my only delight". They were finally completed near the end of 1623. In his attempts to finance the printing of the tables, Kepler began by claiming the arrears due to him by Rudolph. From the Imperial Court in

Vienna en, Viennese , iso_code = AT-9 , registration_plate = W , postal_code_type = Postal code , postal_code = , timezone = CET , utc_offset = +1 , timezone_DST ...

he was sent to three other towns to which the debt was transferred. After a year of roaming the country, he was eventually able to raise 2000

florin The Florentine florin was a gold coin struck from 1252 to 1533 with no significant change in its design or metal content standard during that time. It had 54 grains (3.499 grams, 0.113 troy ounce) of nominally pure or 'fine' gold with a purcha ...

s (out of 6299 owed to him), which sufficed to pay for the paper. He paid for the printing out of his own pocket. It was initially supposed to be printed in

Linz Linz ( , ; cs, Linec) is the capital of Upper Austria and third-largest city in Austria. In the north of the country, it is on the Danube south of the Czech border. In 2018, the population was 204,846. In 2009, it was a European Capital of ...

, where he resided at the time, but the chaos of the

Thirty Years' War The Thirty Years' War was one of the longest and most destructive conflicts in European history The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (80 ...

(first the garrisoning of soldiers in the town, after which a siege of the revolting peasantry, which almost resulted in the burning of the manuscript) prompted him to leave. He began the enterprise anew in

Ulm Ulm () is a city in the German state of Baden-Württemberg, situated on the river Danube on the border with Bavaria. The city, which has an estimated population of more than 126,000 (2018), forms an urban district of its own (german: link=no, ...

. There, after many quarrels with the printer Jonas Saur, the first edition of a thousand copies was completed in September 1627, in time for the annual book mart in the

Frankfurt Fair Messe Frankfurt () is the world's largest trade fair, congress and event organizer with its own exhibition grounds. The organisation has 2,500 employees at some 30 locations, generating annual sales of around €661 million. Its services inclu ...

. While publishing the ''Rudolphine Tables'', Kepler was hard-pressed to fight off Tycho's numerous relatives. During the publication process, these relatives repeatedly tried to obtain control of the observations and the profit from the publication of the tables. Tycho had intended to dedicate the tables to Emperor Rudolf II, but by 1627, when the tables were published, Rudolf II had been dead for 15 years, so instead the tables were dedicated to Emperor Ferdinand II but are named after Rudolph II.

The book, written in Latin, contains tables for the positions of the 1,005 stars measured by Tycho Brahe, and more than 400 stars from

Ptolemy Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importanc ...

and Johann Bayer, with directions and tables for locating the moon and the planets of the Solar System. Included are function tables of

logarithm In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a number to the base is the exponent to which must be raised, to produce . For example, since , the ''logarithm base'' 10 o ...

s (a useful computational tool that had been described in 1614 by

John Napier John Napier of Merchiston (; 1 February 1550 – 4 April 1617), nicknamed Marvellous Merchiston, was a Scottish landowner known as a mathematician, physicist, and astronomer. He was the 8th Laird of Merchiston. His Latinized name was Ioann ...

) and antilogarithms, and instructive examples for computing planetary positions. For most stars these tables were accurate to within one

arc minute A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The n ...

, and included corrective factors for

atmospheric refraction Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. This refraction is due to the velocity of light t ...

. A map of the world was also included. A scroll in the lower left panel of the map is inscribed with instructions on how to use the map and a lunar distance measurement to calculate longitude: it states that by observing the edge of the Moon's disc in relation to a known star, or a lunar eclipse, it is possible to calculate longitude at the point of observation by calculating local time and comparing it to the time stated in the tables. For this purpose, Kepler needed his map to be as up-to-date as possible, and it is remarkable for being one of the first to show the Dutch discoveries of the west coast of Australia, Eendracht Land and Dedels Land; this information was apparently taken from the ''Nova Totius Terrarum Orbis Geographica ac Hydrographica Tabula'' by Jodocus Hondius II, published in Amsterdam in 1625. Hondius derived his geographical knowledge of Australia from the unpublished 1622 map of the Indian Ocean by Hessel Gerritz. A time scale along the Equator on Kepler's map indicates the hours to be added or subtracted for determining longitude (one hour equals 15 degrees longitude).

Use of the tables

The tables were sufficiently accurate to predict a

transit of Mercury frameless, upright=0.5 A transit of Mercury across the Sun takes place when the planet Mercury passes directly between the Sun and a superior planet. During a transit, Mercury appears as a tiny black dot moving across the Sun as the planet obs ...

observed by

Pierre Gassendi Pierre Gassendi (; also Pierre Gassend, Petrus Gassendi; 22 January 1592 – 24 October 1655) was a French philosopher, Catholic priest, astronomer, and mathematician. While he held a church position in south-east France, he also spent much tim ...

in 1631 and a

transit of Venus frameless, upright=0.5 A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During a trans ...

observed by Jeremiah Horrox in 1639. Adam Schall von Bell, a Jesuit in China, used the tables to complete a reform of the

Chinese calendar The traditional Chinese calendar (also known as the Agricultural Calendar ��曆; 农历; ''Nónglì''; 'farming calendar' Former Calendar ��曆; 旧历; ''Jiùlì'' Traditional Calendar ��曆; 老历; ''Lǎolì'', is a lunisolar calendar ...

in 1635.

References

Bibliography

* * Robert J. King, “Johannes Kepler and Australia”, ''The Globe,'' no.90, 2021, pp.15-24.

External links

*
Universitätsbibliothek Kiel – Digiport: ''Tabulæ Rudolphinæ''
- Bartsch version from 1627, with appendices on Schiller's Christian constellations and Bartsch'es own constellation innovations. *
Tabulæ Rudolphinæ
' from the

NOAA Central Library The NOAA Central Library is the flagship library of the National Oceanic and Atmospheric Administration’s (NOAA) network of over 20 research libraries. It is also a selective federal depository library for United States federal government pub ...

, in PDF and TIFF formats.
Johannes Kepler, ''Tabulæ Rudolphinæ''
archive.org, frontispiece, world map, first half is explanation, second half is tables
''Tabvlæ Rudolphinæ qvibvs astronomicæ scientiæ''
... Typis J. Saurii, 1627. From th
Rare Book and Special Collections Division
at the

Library of Congress The Library of Congress (LOC) is the research library that officially serves the United States Congress and is the ''de facto'' national library of the United States. It is the oldest federal cultural institution in the country. The library is ...

{{Authority control 17th-century Latin books 1627 books Star atlases Astronomical catalogues Astrological texts Tycho Brahe 1627 in science Works by Johannes Kepler Astronomical tables Rudolf II, Holy Roman Emperor