N. R. Pogson

Norman Robert Pogson ( born March 23, 1829 in Nottingham, † June 23, 1891 ) was an English astronomer.

Was Pogson 1851 Assistant at the Radcliffe Observatory, Oxford. From 1858 he was director of Hartwell Hall Observatory in Buckingham. From 1861 he was Director of the Observatory of Madras in India.

Pogson discovered eight asteroids (see list of asteroids ) and 21 variable stars and created a comprehensive catalog of stars. He standardized the scale of brightness of the stars by putting the already introduced by Hipparchus system of size classes in a logarithmic ratio. Then a bright star of the first magnitude is one hundred times brighter than a star of the sixth magnitude, which is in good visibility conditions just still recognizable with the naked eye.

In honor Pogsons a 50 km large crater on the Moon is named after him.