86 Semele is a large and very dark main-belt asteroid with an orbital period of 5.5 years.

[4] This object is classified as a C-type asteroid and is probably composed of carbonates.

Semele was discovered by German astronomer Friedrich Tietjen on 4 January 1866.

The orbit of 86 Semele places it in a 13:6 mean motion resonance with the planet Jupiter.

The computed Lyapunov time for this asteroid is only 6,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.