Jan Schilt (3 February 1894, Gouda – 9 January 1982,

Englewood, New Jersey Englewood is a city in Bergen County, in the U.S. state of New Jersey. Englewood was incorporated as a city by an act of the New Jersey Legislature on March 17, 1899, from portions of Ridgefield Township and the remaining portions of Engle ...

) was a Dutch-American

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 ...

, inventor of the Schilt

photometer A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, ...

Biography

Schilt was born in 1894 in the Netherlands, and educated there under

Jacobus Kapteyn Jacobus Cornelius Kapteyn (19 January 1851 – 18 June 1922) was a Dutch astronomy, astronomer. He carried out extensive studies of the Milky Way. He found that the apparent movement of stars was not randomly distributed but had two preferentia ...

. After the death of Kapteyn in 1922 he finished his PhD thesis in 1924 with

Pieter Johannes van Rhijn Pieter Johannes van Rhijn (24 March 1886 – 9 May 1960) was a Dutch astronomer. Born in Gouda, he studied at Groningen. He served as director at the Sterrenkundig Laboratorium ( Kapteyn Astronomical Institute) in Groningen. He died in Groning ...

'On a Thermo-Electric Method of Measuring Photographic Magnitudes'. This work was mainly done at

Leiden Observatory Leiden Observatory () is an astronomical institute of Leiden University, in the Netherlands. Established in 1633 to house the quadrant of Willebrord Snellius, it is the oldest operating university observatory in the world, with the only older sti ...

where he stayed from 1922 to 1925. He emigrated to the United States in 1925, first to

Mount Wilson Observatory The Mount Wilson Observatory (MWO) is an Observatory#Astronomical observatories, astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson (California), Mount Wilson, a peak in the San Gabrie ...

, in 1926 to

Yale University Observatory The Yale University Observatory, also known as the Leitner Family Observatory and Planetarium, is an astronomical observatory owned and operated by Yale University, and maintained for student use. It is located in Farnham Memorial Gardens near the ...

and in 1931 he was appointed associated professor at Rutherford Observatory. In 1933 he became the Chair of

Columbia University Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...

's astronomy department, a position which he filled until his retirement in 1962, when he was granted the title of Rutherford Professor of Astronomy Emeritus. Schilt's astronomical work included the invention of the Schilt

, a device which measures the light output (

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

) of stars on photographic plates, and, indirectly, their distances. He worked on the motions of star streams in the

Milky Way Galaxy The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are ...

, and was director of the Yale-Columbia Southern Station in

Johannesburg Johannesburg ( , , ; Zulu language, Zulu and Xhosa language, Xhosa: eGoli ) (colloquially known as Jozi, Joburg, Jo'burg or "The City of Gold") is the most populous city in South Africa. With 5,538,596 people in the City of Johannesburg alon ...

and

Canberra Canberra ( ; ) is the capital city of Australia. Founded following the Federation of Australia, federation of the colonies of Australia as the seat of government for the new nation, it is Australia's list of cities in Australia, largest in ...

, as well as Director of the Rutherford Observatory at Columbia. Schilt was noted at Columbia for walking into his classes the first day after the launch of

Sputnik Sputnik 1 (, , ''Satellite 1''), sometimes referred to as simply Sputnik, was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space progra ...

1 and commenting "Well, gentlemen, it is not every day we have something new in the sky to talk about", following which he devoted the entire class to proving that Sputnik had been deliberately launched into an

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

designed to make it invisible from the United States for as long as possible (six weeks). 13,500 items of his papers are contained in the

Rare Book and Manuscript Library The Rare Book and Manuscript Library is the principal repository for the special collections of Columbia University. Located on the sixth floor of Butler Library on the university's Morningside Heights campus, its collections span more than 4,0 ...

of Columbia University.

Honor

Asteroid 2308 Schilt (1967 JM) was named in his honor.

Published works

* *

References

*New York Times obituary, January 11, 1982 *Columbia University Library Bulletin
In memoriam Dr. J. Schilt
by J.H. Oort (1982) {{DEFAULTSORT:Schilt, Jan 1894 births 1982 deaths 20th-century American astronomers 20th-century Dutch astronomers Discoverers of asteroids People from Gouda, South Holland Utrecht University alumni University of Groningen alumni Dutch emigrants to the United States Columbia University faculty 20th-century American inventors

Biography

Honor

Published works

See also

References