57 Mnemosyne

57 Mnemosyne
Orbital diagram
Discovery
Discovered byKarl Theodor Robert Luther
Discovery date22 September 1859
Designations
(57) Mnemosyne
Pronunciation/nɪˈmɒsɪniː/[1]
Named after
Mnemosyne
Main belt
AdjectivesMnemosynean /ˌnɛməsɪˈniːən/, 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)
Eccentricity0.118
2,041.056 d (5.59 a)
68.001°
Inclination15.200°
199.337°
212.848°
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]
25.324±0.002 h[3]
0.215[4]
S
7.03

57 Mnemosyne is a large main belt asteroid. It is a stony S-type asteroid in composition. This object was discovered by Robert Luther on 22 September 1859 in Düsseldorf. Its name was chosen by Martin Hoek, the director of the Utrecht Observatory, in reference to Mnemosyne, a Titaness in Greek mythology.[5]

This asteroid is orbiting in the outer main belt at a distance of 3.149 AU from the Sun with an eccentricity (ovalness) of 0.118 and a period of 5.58811 a. The orbital plane is inclined at an angle of 15.2° to the ecliptic. 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]

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.[8] Subsequent observations at Organ Mesa Observatory in 2019 showed this period was not a good fit to a longer light curve. A period of 25.324±0.002 h was adopted; roughly double the original period.[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 Cite error: The named reference Carry2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Pilcher_2019 was invoked but never defined (see the help page).
  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. ^ Cite error: The named reference Hill1873 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Strand1970 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Ditteon2007 was invoked but never defined (see the help page).