James Craig Watson

James Craig Watson
James Craig Watson (1838-1880).jpg
Portrait of James Craig Watson
Born(1838-01-28)January 28, 1838
Fingal, Ontario
DiedNovember 23, 1880(1880-11-23) (aged 42)
Madison, Wisconsin
Cause of deathperitonitis
EducationUniversity of Michigan, University of Wisconsin
Alma materUniversity of Michigan
OccupationProfessor, physicist, astronomer
Known forDiscovery of comets and asteroids
AwardsLalande Prize
Asteroids discovered: 22 [1]
79 EurynomeSeptember 14, 1863
93 MinervaAugust 24, 1867
94 AuroraSeptember 6, 1867
100 HekateJuly 11, 1868
101 HelenaAugust 15, 1868
103 HeraSeptember 7, 1868
104 KlymeneSeptember 13, 1868
105 ArtemisSeptember 16, 1868
106 DioneOctober 10, 1868
115 ThyraAugust 6, 1871
119 AlthaeaApril 3, 1872
121 HermioneMay 12, 1872
128 NemesisNovember 25, 1872
132 AethraJune 13, 1873
133 CyreneAugust 16, 1873
139 JuewaOctober 10, 1874
150 NuwaOctober 18, 1875
161 AthorApril 19, 1876
168 SibyllaSeptember 28, 1876
174 PhaedraSeptember 2, 1877
175 AndromacheOctober 1, 1877
179 KlytaemnestraNovember 11, 1877

James Craig Watson (January 28, 1838 – November 22, 1880) was a Canadian-American astronomer, discoverer of comets and minor planets, director of the Ann Arbor Observatory, and awarded with the Lalande Prize in 1869.[2]

He was born in the village of Fingal, Ontario Canada. His family relocated to Ann Arbor, Michigan in 1850. At age 15 he was matriculated at the University of Michigan, where he studied the classical languages. He graduated with a BA in 1857 and received a master's degree on examination after two years' study in astronomy under professor Franz Brünnow.[3] He became Professor of Physics and instructor in Mathematics, and in 1863, succeeded him as professor of Astronomy and director of the Theoretical Astronomy in 1868.

He discovered 22 asteroids, beginning with 79 Eurynome in 1863. One of his asteroid discoveries, 139 Juewa was made in Beijing when Watson was there to observe the 1874 transit of Venus. The name Juewa was chosen by Chinese officials (瑞華, or in modern pinyin, ruìhuá). Another was 121 Hermione in 1872, from Ann Arbor, Michigan, and this asteroid was found to have a small asteroid moon in 2002.[4]

He was a member of the most important expeditions for astronomical observation sent out by the United States Government during his time.[3] The first was an expedition to observe the eclipse of the Sun at Mount Pleasant, Iowa, in 1869; the second of a similar expedition to Sicily, in 1870; the third to Beijing, China, to observe the transit of Venus in 1874; the fourth to Wyoming, to observe the total eclipse of the sun in 1878. He was a strong believer in the existence of the planet Vulcan, a hypothetical planet closer to the Sun than Mercury, which is now known not to exist (however the existence of small Vulcanoid planetoids remains a possibility). He believed he had seen such two such planets during his observation of the 1878 solar eclipse.

In 1879, after attempts by the university to retain him, Watson resigned his professorship at Ann Arbor to accept a position the University of Wisconsin, where he hoped to find superior apparatus and instruments for the difficult observations which he had planned. Seeking to silence critics who doubted his claims to have discovered Vulcan, he also personally paid to construct an underground observatory, in a misguided attempt to observe planets in the daytime.[5] This was based on the idea that stars could be seen during the day from the bottom of a well, which is an ancient myth but verifiably incorrect. (It is not merely direct glare from the Sun that hides the stars, but scattered light from the atmosphere above the well.)[6]

Watson died of peritonitis at the age of only 42 and was buried at Forest Hill, Ann Arbor.[3] He had amassed a considerable amount of money through non-astronomical business activities. By bequest he established the James Craig Watson Medal, awarded every two years by the National Academy of Sciences for contributions to astronomy. His successor, Edward Holden, completed Watson's underground observatory, but declared it useless after he found not even the brightest stars could be observed.[5]

Watson won the Lalande Prize given by the French Academy of Sciences for 1869.[7] He was a member of the National Academy of Sciences and the American Philosophical Society. He received the honorary degree of Doctor of Philosophy from the University of Leipzig in 1870, and from Yale College in 1871, and the degree of Doctor of Laws from Columbia in 1877.[3]

The main-belt asteroid 729 Watsonia is named in his honour, as is the lunar crater Watson.[2]


  1. ^ "Minor Planet Discoverers (by number)". Minor Planet Center. 22 June 2016. Retrieved 11 July 2016. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (729) Watsonia. Springer Berlin Heidelberg. p. 70. ISBN 978-3-540-00238-3. Retrieved 11 July 2016. 
  3. ^ a b c d Hinsdale, Burke (1906). History of the University of Michigan. Ann Arbor, MI: University of Michigan. pp. 235–236. 
  4. ^ Linda T. Elkins-Tanton - Asteroids, Meteorites, and Comets (2010) - Page 96 (Google Books)
  5. ^ a b David Baron (2017). American Eclipse. Liveright. p. 217. ISBN 9781631490163. 
  6. ^ "Fact Check: Stars Visible from Well". 
  7. ^ "The Lalande Medal". Appletons' Annual Cyclopedia and Register of Important Events of the Year 1873. vol. 13. 1874. p. 49. 
  • Richard Baum and William Sheehan (1997). In Search of Planet Vulcan, The Ghost in Newton's Clockwork Machine. ISBN 0-306-45567-6. 
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