(100) Hekate

100 Hekate
Discovered byJ. C. Watson
Discovery date11 July 1868
(100) Hekate
Named after
1955 QA
Main belt
AdjectivesHekatean (Hecatæan) /hɛkəˈtən/[1]
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc144.93 yr (52936 d)
Aphelion3.61005 AU (540.056 Gm)
Perihelion2.56919 AU (384.345 Gm)
3.08962 AU (462.201 Gm)
5.43 yr (1983.6 d)
0° 10m 53.357s / day
Earth MOID1.55453 AU (232.554 Gm)
Jupiter MOID1.66378 AU (248.898 Gm)
Physical characteristics
Dimensions88.66±2.0 km[2]
89 km[3]
Mass~1.0×1018 kg
Mean density
~2.7 g/cm³ (estimate)[4]
Equatorial surface gravity
~0.033 m/s²
Equatorial escape velocity
~0.054 km/s
27.066 h (1.1278 d)[2]
0.5555 d [5]
Temperature~154 K
max: 238K (-35°C)
S-type asteroid

Hekate (minor planet designation: 100 Hekate) is a large main-belt asteroid. This is a stony S-type asteroid with a diameter of 87+5
and a sidereal rotation period of 27.07 h.[6] 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 0.22±0.03[6] 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.[7]

Hekate was the 100th asteroid to be discovered, by Canadian-American astronomer J. C. Watson (his fourth discovery) on July 11, 1868.[8] It is named after Hecate, the goddess of witchcraft in Greek mythology, but its name also commemorates it as the hundredth asteroid, as hekaton is Greek for 'hundred'.

A Hekatean occultation of a star was observed on July 14, 2003, from New Zealand.

See also[]


  1. ^ a b "Hecate". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  2. ^ a b c d "100 Hekate". JPL Small-Body Database. Jet Propulsion Laboratory. SPK-ID: 2000100. Retrieved 12 May 2016.
  3. ^ a b "IRAS Minor Planet Survey". Archived from the original on 11 December 2005.
  4. ^ Krasinsky, G. A. (2002). "Hidden Mass in the Asteroid Belt". Icarus. 158: 98. Bibcode:2002Icar..158...98K. doi:10.1006/icar.2002.6837.
  5. ^ "Asteroid Lightcurve Parameters".
  6. ^ a b Marciniak, A.; et al. (May 2019). "Thermal properties of slowly rotating asteroids: results from a targeted survey". Astronomy & Astrophysics. 625: 40. arXiv:1905.06056. Bibcode:2019A&A...625A.139M. doi:10.1051/0004-6361/201935129. A139.
  7. ^ McDonald, S. L. (1948). "General perturbations and mean elements, with representations of 35 minor planets of the Hecuba group". The Astronomical Journal. 53: 199. Bibcode:1948AJ.....53..199M. doi:10.1086/106097.
  8. ^ "Discovery Circumstances: Numbered Minor Planets 1–5000". IAU Minor Planet Center. Retrieved 7 April 2013.

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