[13] In October 2004, a rotational lightcurve of La Plata was obtained from photometric observations during an extensive survey of Koronian asteroids at seven different observatories in the United States.

Lightcurve analysis gave a well-defined rotation period of 15.310 hours with a brightness variation of 0.58 magnitude (U=3).

[9][12] Also in October 2004, an alternative period of 14.174 hours was obtained by French amateur astronomer Laurent Bernasconi (U=2).

[4] According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, La Plata measures between 16.46 and 20.78 kilometers in diameter and its surface has an albedo between 0.1819 and 0.310.

[6][7][8] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1655 and a diameter of 20.71 kilometers based on an absolute magnitude of 10.99.