William Stephen Jacob
William Stephen Jacob (1813–1862) was an English immigrant astronomer in India, who acted as the director of the Madras Observatory from 1848 to 1859. His early claim of 1855 to have detected an exoplanet, in orbit around 70 Ophiuchi, is now thought to have been mistaken.[1]
Life
The seventh child of Stephen Long Jacob (1764–1851), vicar of
After Jacob's arrival at
Jacob concentrated on science, and was appointed in December 1848 director of the Madras Observatory. In poor health, he was sent home on sick leave in 1854–5, and again in 1858–9. A transit-circle by William Simms arrived from England in March 1858, a month before he finally left the observatory, resigning on 13 October 1859.[2]
For the solar eclipse of July 18, 1860, Jacob joined the official expedition to Spain aboard the steamer Himalaya.[4] His project of erecting a mountain observatory at Pune was funded by parliament in 1862. He engaged to work there for three years with a 9-inch equatorial, his own purchase from Noël Paymal Lerebours, and landed at Bombay on 8 August, but died on reaching Pune on 16 August 1862, aged 48. He was elected a fellow of the Royal Astronomical Society in 1849.[2]
Works
Jacob presented to the Royal Astronomical Society in 1848 a catalogue of 244
In the Madras Observations for 1848–52 Jacob published a Subsidiary Catalogue of 1,440 Stars selected from the British Association Catalogue. His re-observation of 317 stars from the same collection in 1853–7 showed that large proper motions had been erroneously attributed to them; the instruments used were a 5-foot transit and a 4-foot mural circle, both by Dollond. The same volume contained 998 measures of 250 double stars made with an equatorial of 6.3 inches aperture constructed for Jacob by Lerebours in 1850. Attempted determinations of stellar parallax gave only the ostensible result of a parallax of 0″.06 for Alpha Herculis.[2]
From his measures of the Saturnian and Jovian systems, printed at the expense of the Indian government, Jacob deduced elements for the
His results of magnetic observations at Madras (1846–1850) were published by Jacob in 1854; those made under his superintendence (1851–1855) by
While in England in 1855 Jacob wrote "A few more words on the Plurality of Worlds" in which he suggested life on other planets ("probably that some of the known planets are inhabited, not very improbable that all of them are"), and described his computation of stellar orbits for the Royal Astronomical Society.[2] Jacob posited that apparent orbital anomalies in the binary star 70 Ophiuchi might be caused by an exoplanet.[5] While these anomalies are now thought to have other causes, this was the first serious claim by an astronomer to have detected an exoplanet using scientific methods: 100 years before the first exoplanet was conclusively detected and well before the science of exoplanets was even in its infancy. Professor David Kipping states that the ‘“claim is so remarkable because Jacob was making tiny measurements (80 milliarc seconds or 22 millionths of a degree) with the naked eye, at a time when he wasn’t even sure whether Newton’s law of gravity held sway in distant parts of the galaxy. While Jacob... was ultimately proved wrong, he had the audacity to try.”[6]
Family
Jacob married in 1844, Elizabeth, fourth daughter of Mathew Coates of Gainsborough, who survived him. They had six sons and two daughters.[2]
Notes
- ISBN 978-1-4614-0644-0.
- ^ a b c d e f g h i j k Lee, Sidney, ed. (1892). . Dictionary of National Biography. Vol. 29. London: Smith, Elder & Co.
- doi:10.1093/ref:odnb/14576. (Subscription or UK public library membershiprequired.)
- ^ Jacob, W.S. (1861). "Notes on the Total Eclipse of the Sun of July 18, 1860 as observed in Spain". Edinburgh New Philosophical Journal. 13 (1): 1–6.
- ^ Monthly Notices of the Royal Astronomical Society, Volume 15, Issue 9, July 1855, Pages 228–230
- ^ Professor David Kipping, Columbia University Dept of Astronomy, Cool Worlds video series
External links
- Attribution
This article incorporates text from a publication now in the public domain: Lee, Sidney, ed. (1892). "Jacob, William Stephen". Dictionary of National Biography. Vol. 29. London: Smith, Elder & Co.