Astronomy:185 Eunike
 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 | |
| Minor planet category | 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) |
| |{{{apsis}}}|helion}} | 3.0924 astronomical unit|AU (462.62 Gm) |
| |{{{apsis}}}|helion}} | 2.3843 AU (356.69 Gm) |
| 2.7383 AU (409.64 Gm) | |
| Eccentricity | 0.12930 |
| Orbital period | 4.53 yr (1655.1 d) |
| Mean anomaly | 327.48° |
| Mean motion | 0° 13m 3.036s / day |
| Inclination | 23.238° |
| Longitude of ascending node | 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] |
| Rotation period | 21.797 h (0.9082 d)[2] 21.812 ± 0.001 hours[4] |
| Geometric albedo | 0.0638±0.002 |
| C | |
| Absolute magnitude (H) | 7.62,[2] 7.45 ± 0.01[4] |
Eunike (minor planet designation: 185 Eunike) is a dark and very large main-belt asteroid, with an approximate diameter of 157 kilometres. It has a primitive carbonaceous composition.
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
- ↑ Noah Webster (1884) A Practical Dictionary of the English Language
- ↑ 2.0 2.1 2.2 2.3 "185 Eunike". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=185;cad=1.
- ↑ 3.0 3.1 3.2 Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73: pp. 98–118, doi:10.1016/j.pss.2012.03.009, Bibcode: 2012P&SS...73...98C. See Table 1.
- ↑ 4.0 4.1 4.2 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
- 185 Eunike at AstDyS-2, Asteroids—Dynamic Site
- 185 Eunike at the JPL Small-Body Database
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