periods between 2 and 20 hours. , Fanny ranks among the 250th slowest rotator known to exist. During the same apparition, Tom Polakis at the Command Module Observatory in Arizona obtained a somewhat longer period of hours with a brightness variation of magnitude (). The result supersedes an incorrect period of hours with an amplitude of magnitude from a tentative one-night observation by French amateur astronomers Paul Krafft, Olivier Gerteis, Hubert Gully, Luc Arnold and Matthieu Bachschmidt from 2013 (). Diameter and albedo According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Fanny measures () and () kilometers in diameter and its surface has an albedo of () and (), respectively. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous C-type asteroid of 0.057 and calculates a diameter of 23.86 kilometers based on an absolute magnitude of 11.84. Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), (), () and (). Notes References External links Lightcurve Database Query (LCDB), at www.minorplanet.info Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center 000821 Discoveries by Max Wolf Named minor planets 000821 000821 19160331