magnitude, based on poor data (). In December 2004, and in May 2007, two periods of and with a corresponding amplitude of and magnitude were determined by European astronomers Raymond Poncy as well as Yves Revaz, Raoul Behrend, Alain Klotz, Michel Hernandez, Robert Soubie, Jean-François Gauthier, Bernard Tregon, Pierre Antonini, Laurent Bernasconi, Federico Manzini , Yassine Damerdji and Horacio Correia. The two periods are slightly longer than twice Polakis period solution (). In April 2007, astronomers at the Oakley Observatory , Indiana, obtained a period of hours and an amplitude of magnitude (). In February 2011, French amateur astronomer René Roy determined a period of hours and a brightness variation of magnitude (). A modeled lightcurve by Josef Ďurech and Josef Hanuš, using photometric data including from the Lowell Photometric Database and from the Wide-field Infrared Survey Explorer (WISE) was published in 2018. It gave a sidereal period of and two spin axes at (94.0°, −25.0°) and (269.0°, 4.0°) in ecliptic coordinates (λ, β). Diameter and albedo According to the surveys carried out by the Japanese Akari satellite, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Infrared Astronomical Satellite IRAS, Ani measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0329 and a diameter of 103.52 kilometers based on an absolute magnitude of 9.25. Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), (), () and (). On 7 April 2000, an asteroid occultation of Ani gave a best-fit ellipse dimension of () with a good quality rating of 3. These timed observations are taken when the asteroid passes in front of a distant star. 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 000791 Discoveries by Grigory Neujmin Named minor planets 000791 19140629