13931

13931 is a minor planet in the outer region of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 17 October 1999, by astronomers of the Lincoln Near-Earth Asteroid Research team at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico. The Minor Planet Center, operated by the Smithsonian Astrophysical Observatory, credited the discovery to the team's members, including Kevin Hills, Gregory S. Leonard, and Brian Skiff.

The minor planet orbits the Sun at a distance of 2.9–3.3 AU once every 5 years and 6 months (1,998 days). Its orbit has an eccentricity of 0.06 and an inclination of 11° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Socorro.

13931 has not been named as of 2023. The naming process for minor planets involves the discoverer or their team submitting a proposed name to the Minor Planet Center, which then reviews and approves it if it meets the guidelines. The guidelines include that the name should be 16 characters or less, pronounceable, non-offensive, and not similar to an existing name of a minor planet or comet.