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Top 10 Fascinating Facts about Adriaan van Maanen

Adriaan van Maanen was a Dutch鈥揂merican astronomer.Van Maanen specialized in measuring the minute changes in position of astronomical objects over a period of time, from which he could determine their proper motion and parallax.

These objects included stars, clusters of stars, and nebulae. Let’s take a look at some of the most fascinating facts about him;

1.Van Maanen, born into a well-to-do family in Friesland

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.

2.He is well known for his astrometric measurements of internal motions in spiral nebulae

The spiral galaxy Messier 81 Photo sourced from

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. 

Edwin Bubble’s whose 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.

3.He discovered Van Maanen’s star

Van maanen’s star Photo by Pablo Carlos Budassi

He discovered Van Maanen’s star, which is the closest known solitary white dwarf to the solar system. It is a dense, compact stellar remnant no longer generating energy and has equivalent to about 68% of the Sun’s mass but only 1% of its radius. 

Van Maanen’s Star or Van Maanen 2 was the third white dwarf identified, after 40 Eridani B and Sirius B, and the first solitary example. But Curtis rejected the results of van Maanen due to unrealistic accuracy claimed by him. Later astronomers have re-examined the measurements of Van Maanen, and concluded he had made a serious error.

4.He was also known for faulty results in measurement 

The origin of van Maanen’s measurement errors emerged from his stereo blink comparator, which van Maanen used to compare new plates with plates some 10鈥�20 years old. By blinking between those two plates he could detect small discrepancies on the positions of the objects.

His reference objects were the field stars fairly near the edge of the plates. However he didn’t consider that due to optical effects these stars had been smeared out a little towards the edges, slightly differently between the two plates. This caused systematic errors resulting in imaginary movements.

5.He was also at the centre of a controversy 

Milky Way seen from Western Estonian coast.Photo by Kristian Pikner

In the first and second decade of the 20th century there was a large controversy in the astronomical world about the size of the Milky Way, the size of the universe and the nature of spiral galaxies. The result of this controversy was the great debate in Washington DC between Harlow Shapley and Heber Doust Curtis in April 1920.

Shapley believed that spiral galaxies weren’t systems equal to the Milky Way and in one of his arguments he used the results of Van Maanen, who measured the rotation of the spiral arms of spiral galaxies. After extrapolating his results he concluded that motion of the arms of spiral galaxies had a period of 105 years.

6.Descended from a long line of aristocrats

Descended from a long line of aristocrats, van Maanen was the son of Johan Willem Gerbrand and Catharina Adriana Visser van Maanen, He received his B.A. (1906), M.A. (1909), and Sc.D. (1911) from the University of Utrecht.

From 1908 to 1911 he worked at the University of Groningen, where he met J. C. Kapteyn. In 1911 van Maanen joined the Yerkes Observatory as a volunteer assistant; and in 1912, on Kapteyn鈥檚 recommendation. 

7.His study of the parallaxes of more than 500 stars can be divided into two parts

Van Maanen鈥檚 study of the parallaxes of more than 500 stars can be divided into two parts. He used one group, comprising stars of apparent magnitude +5 to +7 with moderate proper motions, as a distance standard for measuring spectroscopic parallaxes of more distant objects.

Another group, made up of faint stars with great proper motions, led to better under standing of the luminosity function.Van Maanen鈥檚 errors in the determination of the rotations of spirals have been discussed by numerous investigators, including Knut Landmark, in Uppsala Astron.

8.Van Maanen published more than 150 papers

Van Maanen published more than 150 papers, about fifty of them in the Contributions from the Mount Wilson Solar Observatory. Aside from research papers he also wrote popular pieces and biographical sketches and collaborated in the publication of Hemel en Dampkring.

Many of his most important papers appeared in Astrophysical Journal, among them 鈥淟ist of Stars With Proper Motion Exceeding 0.藵50 Annually,鈥� 41 (1915), 187鈥�205; 鈥淧reliminary Evidence of Internal Motion in the Spiral Nebula Messier 101,鈥� 44 (1916), 210鈥�228; and 鈥淭he General Magnetic Field of the Sun. 

9.He wrote several works during his career

He wrote several works during his career including;The proper motions of 1418 stars in and near the clusters and Persei, The photographic determination of stellar parallaxes with the 60- and 100-inch reflectors and Investigation on proper motion. Ninth paper: Internal motion in the spiral nebula Messier 63, N.G.C. 5055.

Others include; Brief van Adriaan van Maanen aan Pibo Antonius Pijnappel (1875-1935) en Elisabeth Antonia Pijnappel, Preliminary evidence of internal motion in the spiral nebula Messier 101,The photographic determination of stellar parallaxes with the 60-inch reflector and many more. 

10.He died on January 26, 1946 aged 61 in USA

He died on January 26, 1946 aged 61,in Pasadena, California, United States of America. He left behind a huge legacy with his theory always a subject in most astronomers. He was also in a member of the Royal Netherlands Academy of Arts and Sciences which he became in 1924.

He ranks highly in lists of famous people across the world and in Netherlands; Among astronomers born in Netherlands, Adriaan van Maanen ranks 19, Among people born in Netherlands, Adriaan van Maanen ranks 840, Among people born in 1884, Adriaan van Maanen ranks 208.He is one of the most sought after astronomer because of his theory always being discussed.