The asteroid was discovered on 18 October 1939, by Finnish astronomer Yrjö Väisälä at Turku Observatory, Southwest Finland.
[3] A photmetric lightcurve analysis by French astronomer Pierre Antonini in 2006, gave a longer than average rotation period of 24 hours (U=1).
[3][9] According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ahti measures between 36.71 and 55.33 kilometers in diameter and its surface has a low albedo between 0.023 and 0.0628.
[4][5][6][7][8] The Collaborative Asteroid Lightcurve Link agrees best with the results obtained by IRAS, and derives a diameter of 36.60 kilometers with an albedo of 0.0479 and an absolute magnitude of 11.1.
[3] This minor planet was named for the god of the sea and of fishing, Ahti (also known as Ahto), mentioned in the Kalevala, a 19th-century work of epic poetry from Karelian and Finnish oral folklore and mythology.