18 Melpomene

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18 Melpomene
Discovery
Discovered by: John Russell Hind
Discovery date: June 24, 1852
Alternative names: none
Minor planet category: Main belt
Orbital characteristics
Epoch October 22, 2004 (JD 2453300.5)
Aphelion distance: 418.414 Gm (2.797 AU)
Perihelion distance: 268.472 Gm (1.795 AU)
Semi-major axis: 343.443 Gm (2.296 AU)
Eccentricity: 0.218
Orbital period: 1270.552 d (3.48 a)
Avg. orbital speed: 19.42 km/s
Mean anomaly: 205.245°
Inclination: 10.126°
Longitude of ascending node: 150.547°
Argument of perihelion: 227.975°
Physical characteristics
Dimensions: 140.6 km (150×125)[1]
Mass: ~2.9×1018 kg
Mean density: 2.0? g/cm³
Equatorial surface gravity: ~0.0393 m/s²
Escape velocity: ~0.0743 km/s
Rotation period: 0.482 21 d (11.573 h) [2]
Albedo: 0.223 [3]
Temperature: ~177 K
Spectral type: S
Absolute magnitude: 6.51

18 Melpomene (IPA: [mɛlˈpʰɒmɪni]) is a large, bright Main belt asteroid. It is composed of silicates and metals.

It was discovered by J. R. Hind on June 24, 1852 and named after Melpomene, the Muse of tragedy in Greek mythology.

Melpomene occulted the star SAO 114159 on December 11, 1978. A possible Melpomenean satellite with a diameter at least 37 km was detected. The satellite candidate received a provisional designation S/1978 (18) 1 [1].

Melpomene was observed with the Hubble Space Telescope in 1993. It was able to resolve the asteroid's slightly elongated shape, but no satellites were detected [2].


[edit] References

  1. ^ http://web.media.mit.edu/~win/hstpub.pdf
  2. ^ http://www.astrosurf.com/aude-old/map_files/AstVarMAP01-2003.htm
  3. ^ http://www.psi.edu/pds/archive/astdata04/simps04/diamalb.tab


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