It orbits the Sun in the inner main-belt at a distance of 2.1–2.5 AU once every 3 years and 6 months (1,286 days).
[1] A first precovery was taken at ESO's La Silla Observatory in 1991, extending the asteroid's observation arc by 5 years prior to its discovery.
[8] In September 2010, a photometric lightcurve analysis of Modra by American astronomer Brian Warner at his Palmer Divide Observatory, Colorado, rendered an unambiguous period of 27.12±0.02 hours with a brightness variation of 0.53 in magnitude (U=3).
[5] A second lightcurve obtained during the wide-field survey at the U.S. Palomar Transient Factory in August 2010, and gave a period of 27.1481±0.0409 hours with an amplitude of 0.42 (U=2).
[2] The approved naming citation was published by the Minor Planet Center on 28 September 1999 (M.P.C.