[2] Benjamina is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.
[3] In September 2004, a rotational lightcurve of Benjamina was obtained from photometric observations by French amateur astronomer Laurent Bernasconi.
Follow-up observation by his college René Roy in March 2018, determined a concurring period of 9.705±0.003 hours but with a much higher amplitude of 0.60±0.10 magnitude (U=2).
It showed a sidereal period of 9.7080±0.0002 hours, and gave a spin axis at (354.0°, 80.0°) in ecliptic coordinates (λ, β).
[5][10] The Collaborative Asteroid Lightcurve Link adopts the result from IRAS, that is, an albedo of 0.0559 and a diameter of 80.53 kilometers based on an absolute magnitude of 9.22.