Norman Robert Pogson, CIE was an English astronomer who worked in India at the Madras observatory. He discovered several minor planets and made observations on comets. He introduced a mathematical scale of stellar magnitudes with the ratio of two successive magnitudes being the fifth root of one hundred (~2.512) and referred to as Pogson's ratio.

The Madras Observatory was an astronomical observatory which had its origins in a private observatory set up by William Petrie in 1786 and later moved and managed by the British East India Company from 1792 in Madras. The main purpose for establishing it was to assist in navigation and mapping by recording the latitude and maintaining time standards. In later years the observatory also made observations on stars and geomagnetism. The observatory ran from around 1792 to 1931 and a major work was the production of a comprehensive catalogue of stars.