Charles Pritchard 251049 163077921 2007-10-08T12:46:54Z BOTijo 3729068 +DEFAULTSORT '''Charles Pritchard''' ([[February 29]], [[1808]]–[[May 28]], [[1893]]) was a [[United Kingdom|British]] [[astronomer]]. He was born at [[Alberbury]], [[Shropshire]]. At eighteen he was enrolled as a [[sizar]] at [[St John's College, Cambridge]], graduating in 1830 as fourth [[Wrangler (University of Cambridge)|wrangler]]. In 1832 he was elected a fellow of his college, and in the following year he was ordained, and became head of a private school at [[Stockwell]]. From [[1834]] to [[1862]] he was headmaster of [[Clapham, London|Clapham]] [[grammar school]]. He then retired to [[Freshwater, Isle of Wight|Freshwater]], in the [[Isle of Wight]], and took an active interest in the affairs of the [[Royal Astronomical Society]], of which he became honorary secretary in 1862 and president in 1866. His sister, Margaret died this same year. His career as a professional astronomer began in [[1870]], when he was elected [[Savilian professor of astronomy]] at the [[University of Oxford]]. At his request the university decided to build a fine equatorial [[telescope]] for the instruction of his class and for purposes of research, a scheme which, as a result of [[Warren de la Rue]]'s munificent gift of instruments from his private observatory at [[Cranford, England|Cranford]], expanded into the establishment of the new university [[observatory]]. By De la Rue's advice, Pritchard began his career there with a determination of the physical [[libration]] of the [[moon]], or the [[nutation]] of its [[Axis_of_rotation|axis]]. In [[1882]] Pritchard commenced a systematic study of stellar [[Photometry (astronomy)|photometry]]. For this purpose he employed an instrument known as the "[[wedge photometer]]", with which he measured the relative brightness of 2,784 stars between the [[North Pole]] and about -10° [[declination]]. The results were published in 1885 in his ''Uranometria Nova Oxoniensis'', and their importance was recognized by the bestowal in [[1886]] upon him, conjointly with Professor [[Edward Charles Pickering|Pickering]], of the [[Gold Medal of the Royal Astronomical Society]]. He then decided to experiment with applying [[photography]] to the determination of [[stellar parallax]]. With the object of testing the capabilities of the method, he took for his first essay the well-known star [[61 Cygni]], and his results agreed so well with those previously attained that he undertook the systematic measurement of the parallaxes of second-magnitude stars, and published the outcome in the third and fourth volumes of the ''Publications of the Oxford University Observatory''. Although some lurking errors impaired the authority of the concluded parallaxes this work ranks as a valuable contribution to astronomy, since it showed the possibility of employing photography in such delicate investigations. When an international survey of the heavens was proposed, the zone between 25° and 31° north declination was allotted to him, and at the time of his death some progress had been made in recording its included stars. Pritchard became a fellow of [[New College, Oxford]], in 1883, and an honorary fellow of [[St John's College, Cambridge]], in 1886. He was elected a fellow of the [[Royal Society]] in 1840, and in 1892 was awarded one of the royal medals for his work on [[photometry (astronomy)|photometry]] and stellar [[parallax]]. ==References== See ''Proc. Roy. Soc.'' liv. 3; ''Astr. and Astrophysics'', xii. 592; J Foster, ''Oxford Men and their Colleges'', p. 206; ''Hist. Register of the Univ. of Oxford'', p. 95; ''[[The Times]]'' ([[May 30]], [[1893]]); CJ Robinson's ''Register of Merchant Taylors' School'', ii. 210; ''Charles Pritchard, D.D., Memoirs of his Life'', by Ada Pritchard (London, 1897). *{{1911}} ==External links== * [http://adsabs.harvard.edu//full/seri/MNRAS/0046//0000265.000.html Awarding of RAS gold medal] ===Obituaries=== * [http://adsabs.harvard.edu//full/seri/MNRAS/0054//0000198.000.html MNRAS '''54''' (1894) 198] * [http://adsabs.harvard.edu//full/seri/Obs../0016//0000256.000.html Obs '''16''' (1894) 256] {{DEFAULTSORT:Pritchard, Charles}} [[Category:1808 births]] [[Category:1893 deaths]] [[Category:People from Shropshire]] [[Category:Alumni of St John's College, Cambridge]] [[Category:English astronomers]] [[Category:Fellows of the Royal Society]] [[Category:Fellows of New College, Oxford]] [[fr:Charles Pritchard]] [[ja:チャールズ・プリチャード]] [[sv:Charles Pritchard]]