Johannes Stadius or Estadius (

Dutch Dutch or Nederlands commonly refers to: * Something of, from, or related to the Netherlands ** Dutch people as an ethnic group () ** Dutch nationality law, history and regulations of Dutch citizenship () ** Dutch language () * In specific terms, i ...

: ''Jan Van Ostaeyen'';

French French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

: ''Jean Stade'') (ca. 1 May 1527 – 17 June 1579), was a

Flemish Flemish may refer to: * Flemish, adjective for Flanders, Belgium * Flemish region, one of the three regions of Belgium *Flemish Community, one of the three constitutionally defined language communities of Belgium * Flemish dialects, a Dutch dialec ...

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

astrologer Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions ...

, and

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

. He was one of the important late 16th-century makers of

ephemerides In astronomy and celestial navigation, an ephemeris (; ; , ) is a book with tables that gives the trajectory of naturally occurring astronomical objects and artificial satellites in the sky, i.e., the position (and possibly velocity) over time. ...

, which gave the positions of astronomical objects in the sky at a given time or times.

Life

Born ''Jan Van Ostaeyen'' in the town of

Loenhout Loenhout is a village and ''deelgemeente'' (sub-municipality) of the municipality of Wuustwezel in the province of Antwerp, Belgium. The village is located near the Dutch border, and about north-east of the city of Antwerp. History The area ar ...

(''Loennouthesius'', meaning 'from Loenhout', is sometimes appended to his Latin surname) in the

Duchy of Brabant The Duchy of Brabant, a Imperial State, state of the Holy Roman Empire, was established in 1183. It developed from the Landgraviate of Brabant of 1085–1183, and formed the heart of the historic Low Countries. The Duchy comprised part of the Bu ...

, Stadius grew up in the ''Schaliënhuis'' on the old Dorpsstraat, which was one of the oldest houses in Loenhout (today a tavern and restaurant). Not much else is known regarding his youth besides the fact that his parents were not married to each other. After receiving his education at the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

school of

Brecht Eugen Berthold Friedrich Brecht (10 February 1898 – 14 August 1956), known as Bertolt Brecht and Bert Brecht, was a German theatre practitioner, playwright, and poet. Coming of age during the Weimar Republic, he had his first successes as a ...

, Stadius studied

mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

geography Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...

, and

history History is the systematic study of the past, focusing primarily on the Human history, human past. As an academic discipline, it analyses and interprets evidence to construct narratives about what happened and explain why it happened. Some t ...

at the

Old University of Leuven The Old University of Leuven (or of Louvain) is the name historians give to the Medieval university, university, or ''studium generale'', founded in Leuven, Duchy of Brabant, Brabant (then part of the Burgundian Netherlands, now part of Belgium ...

, where one of his teachers was

Gemma Frisius Gemma Frisius (; born Jemme Reinerszoon; December 9, 1508 – May 25, 1555) was a Dutch physician, mathematician, cartographer, philosopher, and instrument maker. He created important globes, improved the mathematical instruments of his day ...

. After completing his studies, he became a professor of mathematics at his alma mater. In 1554 he left his home country and travelled to

Turin Turin ( , ; ; , then ) is a city and an important business and cultural centre in northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. The city is main ...

, where he enjoyed the patronage of the powerful Duke of

Savoy Savoy (; )  is a cultural-historical region in the Western Alps. Situated on the cultural boundary between Occitania and Piedmont, the area extends from Lake Geneva in the north to the Dauphiné in the south and west and to the Aosta Vall ...

. Stadius subsequently worked in

Cologne Cologne ( ; ; ) is the largest city of the States of Germany, German state of North Rhine-Westphalia and the List of cities in Germany by population, fourth-most populous city of Germany with nearly 1.1 million inhabitants in the city pr ...

Brussels Brussels, officially the Brussels-Capital Region, (All text and all but one graphic show the English name as Brussels-Capital Region.) is a Communities, regions and language areas of Belgium#Regions, region of Belgium comprising #Municipalit ...

and

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

. In Paris, he debated with the trigonometrist

Maurice Bressieu Maurice may refer to: *Maurice (name), a given name and surname, including a list of people with the name Places * or Mauritius, an island country in the Indian Ocean *Maurice, Iowa, a city *Maurice, Louisiana, a village *Maurice River, a trib ...

Grenoble Grenoble ( ; ; or ; or ) is the Prefectures in France, prefecture and List of communes in France with over 20,000 inhabitants, largest city of the Isère Departments of France, department in the Auvergne-Rhône-Alpes Regions of France, region ...

and made

astrological Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions of celesti ...

predictions for the French court. In his ''Tabulae Bergenses'' (1560), Stadius calls himself both royal mathematician (of

Philip II of Spain Philip II (21 May 152713 September 1598), sometimes known in Spain as Philip the Prudent (), was King of Spain from 1556, King of Portugal from 1580, and King of Naples and List of Sicilian monarchs, Sicily from 1554 until his death in 1598. He ...

) and mathematician to the Duke of Savoy.

''Ephemerides''

During his stay in Brussels Stadius published his first work, the ''Ephemerides novae et auctae'', first published by the publisher Arnold Birckmann of

in 1554. An ''

ephemeris In astronomy and celestial navigation, an ephemeris (; ; , ) is a book with tables that gives the trajectory of naturally occurring astronomical objects and artificial satellites in the sky, i.e., the position (and possibly velocity) over tim ...

'' (plural: ''ephemerides'') (from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

word ''ephemeros'', "daily") was, traditionally, a table providing the positions (given in a

Cartesian coordinate system In geometry, a Cartesian coordinate system (, ) in a plane (geometry), plane is a coordinate system that specifies each point (geometry), point uniquely by a pair of real numbers called ''coordinates'', which are the positive and negative number ...

, or in

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the equinox (celestial coordinates), March equinox to the (hour circle of the) point in questio ...

and

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or ...

or, for astrologers, in

longitude Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...

along the

zodiac The zodiac is a belt-shaped region of the sky that extends approximately 8° north and south celestial latitude of the ecliptic – the apparent path of the Sun across the celestial sphere over the course of the year. Within this zodiac ...

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

), of the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

, the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

, and the

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

s in the

sky The sky is an unobstructed view upward from the planetary surface, surface of the Earth. It includes the atmosphere of Earth, atmosphere and outer space. It may also be considered a place between the ground and outer space, thus distinct from ...

at a given moment in

time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...

; the astrological positions are usually given for either

noon Noon (also known as noontime or midday) is 12 o'clock in the daytime. It is written as 12 noon, 12:00 m. (for '' meridiem'', literally 12:00 midday), 12 p.m. (for ''post meridiem'', literally "after midday"), 12 pm, or 12:00 (using a 24-hour cl ...

midnight Midnight is the transition time from one day to the next – the moment when the date changes, on the local official clock time for any particular jurisdiction. By clock time, midnight is the opposite of noon, differing from it by 12 hours. ...

depending on the particular ephemeris that is used. This work posited a link between mathematics and medicine and was influential on

Tycho Brahe Tycho Brahe ( ; ; born Tyge Ottesen Brahe, ; 14 December 154624 October 1601), generally called Tycho for short, was a Danish astronomer of the Renaissance, known for his comprehensive and unprecedentedly accurate astronomical observations. He ...

and

Nostradamus Michel de Nostredame (December 1503 – July 1566), usually Latinisation of names, Latinised as Nostradamus, was a French Astrology, astrologer, apothecary, physician, and reputed Oracle, seer, who is best known for his book ''Les Prophéti ...

. Stadius had been encouraged to publish the ''Ephemerides'' by his old teacher

. Frisius had in a letter written in 1555 urged Stadius not to be afraid of being accused of believing in a moving earth and a stationary sun (i.e. the theory of

Copernicus Nicolaus Copernicus (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a mathematical model, model of Celestial spheres#Renaissance, the universe that placed heliocentrism, the Sun rather than Earth at its cen ...

) or of abandoning the medieval

Alfonsine Tables The ''Alfonsine Tables'' (, ), sometimes spelled ''Alphonsine Tables'', provided data for computing the position of the Sun, Moon and planets relative to the fixed stars. The tables were named after Alfonso X of Castile, who sponsored their cr ...

in favor of his own observations. In this letter Frisius further wrote that the system devised by

gave a better understanding of planetary distances, as well as of certain features of retrograde motion. Frisius' letter was published in several editions of the ''Ephemerides''. The 1556 edition (Cologne) ''Ephemerides novae et exactae Ioannis Stadii Leonnovthesii ab anno 1554. ad annum 1570. ...'' can be consulted onlin
via KU Leuven Special Collections

Death and legacy

Stadius died in Paris where he is buried. The inscription on his epitaph states that he died on 17 June 1579 and that he had lived for nearly 52 years and 2 months. Stadius' estimated birth date of 1 May 1527 is based on this inscriptio

The

lunar crater Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated. History The wo ...

Stadius is named after Stadius.

External links

Prospector: Johannes Stadius

Flapuit: Johannes Stadius

*James H. Holden: A History of Horoscopic
AstrologySteven Vanden Broecke: The Limits of Influence: Pico, Louvain, and the Crisis of Renaissance Astrology
*(in Dutch

Joannes Stadius

References

External links

{{DEFAULTSORT:Stadius, Johannes 16th-century Dutch astronomers 16th-century mathematicians from the Holy Roman Empire People from Wuustwezel Old University of Leuven alumni 1527 births 1579 deaths Flemish astronomers Flemish mathematicians 16th-century astrologers Academic staff of the Old University of Leuven Scientists from the Habsburg Netherlands

Life

''Ephemerides''

Death and legacy

External links

Further reading

References

External links