rotation period of hours with a brightness variation of magnitude (). Two tentative lightcurves were obtained by Pierre Antonini in June 2010, and by Robin Esseiva, Nicolas Esseiva and Raoul Behrend in April 2015; both with a period of hours and an amplitude of and magnitude, respectively (). In 2016, a modeled lightcurves using photometric data from various sources, rendered a concurring sidereal period of hours and two spin axes of (247.0°, −29.0°) and (86.0°, −63.0°) in ecliptic coordinates. Diameter and albedo According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Hildrun measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0437 and a diameter of 66.59 km based on an absolute magnitude of 9.9. Further published mean-diameters and albedos by the WISE team include (), () and () with corresponding albedos of (), () and (). Notes References External links 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 000928 Discoveries by Karl Wilhelm Reinmuth Named minor planets 19200223