86 Semele

86 Semele
Orbit of 86 Semele on 1 Jan 2009
Discovery
Discovered byFriedrich Tietjen
Discovery date4 January 1866
Designations
(86) Semele
Pronunciation/ˈsɛmɪlə/[1]
Named after
Semele
Main belt
AdjectivesSemelean /sɛmɪˈleɪən/[2]
Orbital characteristics[3]
Epoch 31 December 2006 (JD 2454100.5)
Aphelion562.652 Gm (3.761 AU)
Perihelion369.116 Gm (2.467 AU)
465.884 Gm (3.114 AU)
Eccentricity0.208
2,007.366 d (5.50 a)
16.69 km/s
264.875°
Inclination4.822°
86.452°
307.886°
Physical characteristics
Dimensions120.6 km
Mass1.8×1018 kg
Equatorial surface gravity
0.0337 m/s²
Equatorial escape velocity
0.0638 km/s
16.641±0.001 h[4]
0.047 [5]
C
8.54

86 Semele is a large and very dark main-belt asteroid with an orbital period of 5.5 years. It is rotating with a period of 16.6 hours, and varies in magnitude by 0.13 during each cycle.[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.[6] It was his first and only asteroid discovery. It is named after Semele, the mother of Dionysus in Greek mythology.

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. This Lyapunov time is the second lowest among the first 100 named minor planets.[7]

  1. ^ "Semele". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 1 March 2020.
  2. ^ Robert Calverley Trevelyan (1898) Mallow and Asphadel, p. 4.
  3. ^ Cite error: The named reference JPL was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Pilcher2020 was invoked but never defined (see the help page).
  5. ^ Asteroid Data Sets Archived 2009-12-17 at the Wayback Machine
  6. ^ Cite error: The named reference IAU_MPC was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Sidlichovsky was invoked but never defined (see the help page).