Hendrik Christoffel "Henk" van de Hulst (19 November 1918 – 31 July 2000) was a Dutch astronomer and mathematician. In 1944, while a student in Utrecht, he predicted the existence of the 21 cm hyperfine line of neutral interstellar hydrogen. After this line was discovered, he participated, with Jan Oort and C.A. Muller, in the effort to use radio astronomy to map out the neutral hydrogen in our

galaxy A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

, which first revealed its spiral structure. Motivated by the scattering in cosmic dust, he studied light scattering by spherical particles and wrote his doctoral thesis on the topic, subsequently formulating the anomalous diffraction theory. He spent most of his career at

Leiden University Leiden University (abbreviated as ''LEI''; nl, Universiteit Leiden) is a Public university, public research university in Leiden, Netherlands. The university was founded as a Protestant university in 1575 by William the Silent, William, Prince o ...

, retiring in 1984. He published widely in astronomy, and dealt with the solar corona, and interstellar clouds. After 1960 he was a leader in international space research projects. In 1956 he became member of the

Royal Netherlands Academy of Arts and Sciences The Royal Netherlands Academy of Arts and Sciences ( nl, Koninklijke Nederlandse Akademie van Wetenschappen, abbreviated: KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed ...

Books

*van de Hulst, H.C., ''Light Scattering by Small Particles'', New York, ( Wiley, 1957;

Dover Dover () is a town and major ferry port in Kent, South East England. It faces France across the Strait of Dover, the narrowest part of the English Channel at from Cap Gris Nez in France. It lies south-east of Canterbury and east of Maidstone ...

, 1981), . *van de Hulst, H.C., ''Multiple Light Scattering'', New York, Academic Press, 1980, .

Honors

Awards * Henry Draper Medal of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

(1955) * Eddington Medal of the Royal Astronomical Society (1955) *

Rumford Medal The Rumford Medal is an award bestowed by Britain's Royal Society every alternating year for "an outstandingly important recent discovery in the field of thermal or optical properties of matter made by a scientist working in Europe". First awar ...

of the Royal Society (1964) * Bruce Medal of the Astronomical Society of the Pacific (1978) * Karl Schwarzschild Medal of the Astronomische Gesellschaft (1995) Named after him *

Asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

2413 van de Hulst * van de Hulst approximation

Honors

* elected to the American Philosophical Society (1960) * elected to the American Academy of Arts and Sciences (1960) * elected to the United States

(1977)

References

Bibliography

* 1918 births 2000 deaths 20th-century Dutch astronomers Utrecht University alumni Leiden University faculty Scientists from Utrecht (city) Foreign Members of the Royal Society Foreign associates of the National Academy of Sciences Members of the Royal Netherlands Academy of Arts and Sciences {{Europe-astronomer-stub Members of the American Philosophical Society