William Parsons, 3d earl of Rosse, Lord Rosse, Lord Oxmantown (1800–67)

Astronomer. Styled Lord Oxmantown from 1801. Constructed a telescope with a 72-inch disc at Birr Castle, Ireland, in 1845. Made important observations on nebulae. President of the Royal Society, 1848–54. Appointed chancellor of the University of Dublin in 1862. Succeeded as 3d earl of Rosse in 1841. FRS 1831.