57 Mnemosyne

Mnemosyne (minor planet designation: 57 Mnemosyne) is a large main belt asteroid. It is an S-type asteroid in composition. It was discovered by Robert Luther on 22 September 1859 from Düsseldorf. Its name was chosen by Martin Hoek, director of the Utrecht Observatory, in reference to Mnemosyne, a Titaness in Greek mythology.[5] The orbital period of this asteroid is close to a 2:1 commensurability with Jupiter, which made it useful for perturbation measurements to derive the mass of the planet.[6][7]

57 Mnemosyne
Discovered byKarl Theodor Robert Luther
Discovery date22 September 1859
(57) Mnemosyne
Named after
Main belt
AdjectivesMnemosynean /ˌnɛməsɪˈnən/, Mnemosynian /nɛməˈsɪniən/
Orbital characteristics
Epoch December 31, 2006 (JD 2454100.5)
Aphelion526.785 Gm (3.521 AU)
Perihelion415.379 Gm (2.777 AU)
471.082 Gm (3.149 AU)
2041.056 d (5.59 a)
Physical characteristics
Dimensions113.01±4.46 km[2]
Mass(1.26±0.24)×1019 kg[2]
Mean density
16.62±3.73 g/cm3[2]
12.06±0.03 h[3]

Photometry measurements made at the Oakley Observatory during 2006 produced a lightcurve with a rotation period of 12.06±0.03 h and an amplitude of 0.14±0.01 in magnitude.[3] It has an estimated span of 113.01±4.46 km and a mass of (1.26±0.24)×1019 kg.[2]


  1. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  2. ^ a b c d Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, vol. 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
  3. ^ a b Ditteon, Richard; Hawkins, Scot (September 2007), "Asteroid Lightcurve Analysis at the Oakley Observatory - October-November 2006", The Minor Planet Bulletin, 34 (3): 59–64, Bibcode:2007MPBu...34...59D.
  4. ^ Asteroid Data Sets Archived 2009-12-17 at the Wayback Machine
  5. ^ Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names. Springer Science & Business Media. p. 20. ISBN 978-3-540-00238-3.
  6. ^ Hill, G. W. (1873), "On the Derivation of the Mass of Jupiter from the Motion of Certain Asteroids", Memoirs of the American Academy of Arts and Sciences, 9 (2): 417–420, JSTOR 25058008.
  7. ^ Strand, K. A. (January 1970), "U.S. Naval Observatory, Washington, D.C. Report 1968-1969.", Bulletin of the Astronomical Society, 2: 144–149, Bibcode:1970BAAS....2..144S.

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