They gave a concurring period of 11.595, 11.596 and 11.599 hours with an amplitude between 0.34 and 0.73 magnitude (). A high brightness amplitude is indicative for a non-spherical, elongated shape "(see below)". According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, and astronomers revisiting the data from these three space-based telescopes, "Anchises" measures between 99.55 and 136 kilometers in diameter and its surface has an albedo between 0.0308 and 0.050. The "Collaborative Asteroid Lightcurve Link" adopts the results obtained by IRAS, that is an albedo of 0.0308 and a diameter of 126.27 kilometers based on an absolute magnitude of 8.89. This makes it the 7th largest Jupiter trojan only according to IRAS (126 km), and would be at least 6th should the size indeed prove to be 136 km or more, while it is much smaller and a few places further down the list according to the NEOWISE survey catalog (<100 km). One of the reasons for the large discrepancies in diameter estimates is possibly related to the results being derived from single-epoch observations of the asteroid, which is known for its large brightness variations "(see above)". In 2012, an international collaboration revisited the WISE, IRAS and Akari observational data. As already suggested by the body's high brightness amplitude, the astronomers found that "Anchises" is significantly elongated, with best-fit dimensions of , which corresponds to a mean diameter of kilometers. Due to a small phase coefficient and a lack of any noticeable opposition effect, astronomers at Cerro Tololo concluded that this Jupiter trojan asteroid possesses an unusually smooth surface texture – far less rough than the great majority of asteroids. In case the surface of "Anchises" consist of bare rock, with high thermal inertia, the body's true diameter could be significantly greater than the estimated 136 kilometers, the study concludes.