Adriaan van Maanen, Dutch-American astronomer and academic (b. 1884)
Adriaan van Maanen (March 31, 1884 – January 26, 1946) was a Dutch–American astronomer.
Van Maanen, born into a well-to-do family in Friesland, studied astronomy at the University of Utrecht (earning his Ph.D. in 1911) and worked briefly at the University of Groningen. In 1911, he came to the United States to work as a volunteer in an unpaid capacity at Yerkes Observatory. Within a year he got a position at the Mount Wilson Observatory, where he remained active until his death in 1946.
He discovered Van Maanen's star.
He is well known for his astrometric measurements of internal motions in spiral nebulae. Believing that nebulae were local, stellar and gaseous systems that existed in our galaxy, his measurements came to be at odds with Edwin Hubble's discovery that the Andromeda Nebula and other spiral nebulae were extragalactic objects. The speed of rotation he calculated for the nebulae, if Hubble were correct as to their extragalactic nature, would have had their Cepheid stars moving at speeds faster than that of light. In 1935, it was decided that since Hubble's calculations of extragalactic Cepheid distances were correct, ergo van Maanen's astrometric measurements had to be incorrect.
In 1924 he became member of the Royal Netherlands Academy of Arts and Sciences.
1946Jan, 26
Adriaan van Maanen
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Events on 1946
- 11Mar
Auschwitz concentration camp
Rudolf Höss, the first commandant of Auschwitz concentration camp, is captured by British troops. - 2Sep
Jawaharlal Nehru
The Interim Government of India is formed, headed by Jawaharlal Nehru as Vice President with the powers of a Prime Minister. - 8Sep
Bulgaria
A 95.6% vote in favor of abolishing the monarchy in Bulgaria. - 23Oct
Flushing, Queens
The United Nations General Assembly convenes for the first time, at an auditorium in Flushing, Queens, New York City. - 19Nov
Iceland
Afghanistan, Iceland and Sweden join the United Nations.