2826 Ahti, provisional designation 1939 UJ, is a carbonaceous asteroid from the outer region of the asteroid belt, about 37 kilometers in diameter. The asteroid was discovered on 18 October 1939, by Finnish astronomer Yrjö Väisälä at Turku Observatory, Southwest Finland. It was named after  Ahti from Finnish mythology.
Orbit and classification
Ahti orbits the Sun in the outer main-belt at a distance of 3.1–3.4 AU once every 5 years and 9 months (2,115 days). Its orbit has an eccentricity of 0.05 and an inclination of 15 ° with respect to the ecliptic.
Ahti has been characterized as a dark C-type asteroid.
lightcurve analysis by French astronomer Pierre Antonini in 2006, gave a longer than average rotation period of 24 hours ( ). The result, however, is considered to be only provisional. U=1 
Diameter and albedo
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.    
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.
minor planet was named for the god of the sea and of fishing, Ahti (also known as Ahto), mentioned in the , a 19th-century work of epic poetry from Karelian and Finnish oral folklore and mythology.
1454 Kalevala is named after the Finish national epic. Ahti is also a common masculine name in Finland. The official naming citation was published by the  Minor Planet Center on 26 May 1983 ( ). M.P.C. 7949
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