185 Eunike is a dark and very large main-belt asteroid, with an approximate diameter of 157 kilometres. It has a primitive carbonaceous composition.
 Orbital diagram | |
| Discovery | |
|---|---|
| Discovered by | C. H. F. Peters, 1878 |
| Discovery date | 1 March 1878 |
| Designations | |
| (185) Eunike | |
| Pronunciation | /juːˈnaɪkiː/[1] |
Named after | Εὐνίκη Eynīkē |
| A878 EA | |
| Main belt | |
| Adjectives | Eunikean /juːnɪˈkiːən/ |
| Orbital characteristics[2] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 131.77 yr (48128 d) |
| Aphelion | 3.0924 AU (462.62 Gm) |
| Perihelion | 2.3843 AU (356.69 Gm) |
| 2.7383 AU (409.64 Gm) | |
| Eccentricity | 0.12930 |
| 4.53 yr (1655.1 d) | |
| 327.48° | |
| 0° 13m 3.036s / day | |
| Inclination | 23.238° |
| 153.84° | |
| 224.01° | |
| Earth MOID | 1.41759 AU (212.068 Gm) |
| Jupiter MOID | 2.40697 AU (360.078 Gm) |
| TJupiter | 3.222 |
| Physical characteristics | |
| Dimensions | 157.51±2.6 km[2] 160.61 ± 5.00 km[3] |
| Mass | (3.56 ± 2.61) × 1018 kg[3] |
Mean density | 1.64 ± 1.21 g/cm3[3] |
| 21.797 h (0.9082 d)[2] 21.812 ± 0.001 hours[4] | |
| 0.0638±0.002 | |
| C | |
| 7.62,[2] 7.45 ± 0.01[4] | |
It was discovered by C. H. F. Peters on March 1, 1878, in Clinton, New York and named after Eunike, a Nereid in Greek mythology whose name means 'happy victory'. The name was chosen to celebrate the Treaty of San Stefano (1878).
Based upon photometric observations made between 2010 and 2014, this asteroid has a rotation period of 21.812 ± 0.001 hours and a brightness variation of 0.08 ± 0.01 in magnitude. At opposition, the absolute magnitude was measured at 7.45 ± 0.01. It displays a hemispheric albedo dichotomy similar to that on 4 Vesta.[4]
As of 17 September 2020, there have been thirteen observed occultations of stars by Eunike.
References
edit- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ a b c d "185 Eunike". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 12 May 2016.
- ^ a b c 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.
- ^ a b c Pilcher, Frederick; et al. (October 2014), "A Comprehensive Photometric Investigation of 185 Eunike", of the Minor Planets Section of the Association of Lunar and Planetary Observers, 41 (4): 244–250, Bibcode:2014MPBu...41..244P.
External links
edit- 185 Eunike at AstDyS-2, Asteroids—Dynamic Site
- 185 Eunike at the JPL Small-Body Database
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