It was discovered on 21 November 1990, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at the Kitami Observatory.
Lightcurve analysis gave a well-defined rotation period of 12.38 hours with a brightness variation of 0.48 magnitude (U=3).
[8] In February 2014, astronomers at the Palomar Transient Factory measured a similar period of 12.369 hours and an amplitude of 0.38 magnitude in the R-band (U=2).
[6] This minor planet was named after the Japanese Amanogawa River that through the town of Kaminokuni on the island of Hokkaido.
[1] The official naming citation was published by the Minor Planet Center on 22 February 1997 (M.P.C.