 According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, "Annika" measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively.The "Collaborative Asteroid Lightcurve Link" derives an albedo of 0.2062 and a diameter of 22.20 kilometers based on an absolute magnitude of 10.6.Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), (), () and ().