18 Melpomene
From Wikipedia, the free encyclopedia
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Discovery
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| Discovered by | John Russell Hind |
| Discovery date | June 24, 1852 |
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Designations
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| Alternative names | none |
| Minor planet category |
Main belt |
| Epoch October 22, 2004 (JD 2453300.5) | |
| Aphelion | 418.414 Gm (2.797 AU) |
| Perihelion | 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) |
| Average orbital speed | 19.42 km/s |
| Mean anomaly | 205.245° |
| Inclination | 10.126° |
| Longitude of ascending node | 150.547° |
| Argument of perihelion | 227.975° |
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Physical characteristics
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| 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 (geometric) [3] |
| Temperature | ~177 K |
| Spectral type | S |
| Apparent magnitude | 7.5[4] to 12.0 |
| Absolute magnitude | 6.51 |
| Angular diameter | 0.23" to 0.059" |
18 Melpomene (pronounced /mɛlˈpɒmɪni/, Greek: Μελπομένη) 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 [3].
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 [4].
[edit] References
- ^ http://web.media.mit.edu/~win/hstpub.pdf
- ^ [1][dead link]
- ^ [2][dead link]
- ^ Donald H. Menzel and Jay M. Pasachoff (1983). A Field Guide to the Stars and Planets, 2nd edition, Boston, MA: Houghton Mifflin, p. 391. ISBN 0395348358.
[edit] External links
- Orbital simulation from JPL (Java) / Ephemeris
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