| Minorplanet: | yes |
| Background: |
|
| 100 Hekate | |
| Discovered: | 11 July 1868 |
| Mpc Name: | (100) Hekate |
| Alt Names: | 1955 QA |
| Adjective: | Hekatean (Hecatæan) |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Aphelion: | 3.61005abbr=onNaNabbr=on |
| Perihelion: | 2.56919AU |
| Semimajor: | 3.08962AU |
| Eccentricity: | 0.16844 |
| Period: | 5.43 yr (1983.6 d) |
| Inclination: | 6.42957° |
| Asc Node: | 127.199° |
| Arg Peri: | 184.736° |
| Dimensions: | 89 km |
| Mass: | ~1.0×1018 kg |
| Density: | ~2.7 g/cm3 (estimate) |
| Surface Grav: | ~0.033 m/s2 |
| Escape Velocity: | ~0.054 km/s |
| Rotation: | 27.066abbr=onNaNabbr=on 0.5555 d[1] |
| Abs Magnitude: | 7.67 |
| Albedo: | 0.192 |
| Single Temperature: | ~154 K max: 238K (-35°C) |
| Mean Motion: | / day |
| Observation Arc: | 144.93 yr (52936 d) |
| Uncertainty: | 0 |
| Moid: | 1.55453AU |
| Jupiter Moid: | 1.66378AU |
| Tisserand: | 3.194 |
100 Hekate is a large main-belt asteroid.
This is a stony S-type asteroid with a diameter of and a sidereal rotation period of . It orbits in the same region of space as the Hygiea asteroid family, though it is actually an unrelated interloper. However, its geometric albedo of is too high, and it is of the wrong spectral class to be part of the dark carbonaceous Hygiea family. It is listed as a member of the Hecuba group of asteroids that orbit near the 2:1 mean-motion resonance with Jupiter.
Hekate was the 100th asteroid to be discovered, by Canadian-American astronomer J. C. Watson (his fourth discovery) on July 11, 1868. It is named after Hecate, the goddess of witchcraft in Greek mythology, but its name also commemorates it as the hundredth asteroid, as ἑκατόν (hekaton) is Greek for 'hundred'.
A Hekatean occultation of a star was observed on July 14, 2003, from New Zealand.