 Orbital diagram | |
| Discovery | |
|---|---|
| Discovered by | Karl Theodor Robert Luther |
| Discovery date | 22 September 1859 |
| Designations | |
| (57) Mnemosyne | |
| Pronunciation | /nɪˈmɒsɪniː/[1] |
Named after | Mnemosyne |
| Main belt | |
| Adjectives | Mnemosynean/ˌnɛməsɪˈniːən/, Mnemosynian/nɛməˈsɪniən/ |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 526.785 Gm (3.521 AU) |
| Perihelion | 415.379 Gm (2.777 AU) |
| 471.082 Gm (3.149 AU) | |
| Eccentricity | 0.118 |
| 2,041.056 d (5.59 a) | |
| 68.001° | |
| Inclination | 15.200° |
| 199.337° | |
| 212.848° | |
| Physical characteristics | |
| Dimensions | 113.01±4.46 km[2] |
| Mass | (1.26±0.24)×1019 kg[2] |
Meandensity | 16.62±3.73 g/cm3[2] |
| 25.324±0.002 h[3] | |
| 0.215[4] | |
| S | |
| 7.03 | |
57 Mnemosyne is a largemain beltasteroid. It is a stonyS-type asteroid in composition. This object was discovered byRobert Luther on 22 September 1859 inDüsseldorf. Its name was chosen byMartin Hoek, the director of theUtrecht Observatory, in reference toMnemosyne, aTitaness inGreek mythology.[5]
This asteroid is orbiting in the outer main belt at a distance of 3.149 AU from the Sun with aneccentricity (ovalness) of 0.118 and aperiod of 5.58811 a. Theorbital plane isinclined at an angle of 15.2° to theecliptic. The orbital period of this asteroid is close to a 2:1commensurability withJupiter, 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 alightcurve with arotation period of12.06±0.03 h and anamplitude of0.14±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 of25.324±0.002 h was adopted; roughly double the original period.[3] It has an estimated span of113.01±4.46 km and a mass of(1.26±0.24)×1019 kg.[2]
