Frederick William Herschel , KH , FRS ( German : Friedrich Wilhelm Herschel ; 15 November 1738 - 25 August 1822 ) was a Hanoverian-born British astronomer , technical expert , and composer .
Sir Frederick William Herschel FRS ( 15 November 1738 - 25 August 1822 ) was a German-British astronomer , the greatest observational astronomer of the day .