181 Eucharis
Eucharis (minor planet designation: 181 Eucharis) is a large, slowly rotating main-belt asteroid that was discovered by French astronomer Pablo Cottenot on February 2, 1878, from Marseille Observatory. It was his only asteroid discovery. This object was named after Eucharis, a nymph from the 17th-century novel Les Aventures de Télémaque.
Orbital diagram | |
| Discovery | |
|---|---|
| Discovered by | Pablo Cottenot |
| Discovery date | 2 February 1878 |
| Designations | |
MPC designation | (181) Eucharis |
| Pronunciation | /ˈjuːkərɪs/ |
Named after | Eucharis |
Alternative designations | A878 CB; 1906 GA |
Minor planet category | Main belt |
| Orbital characteristics | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 123.63 yr (45157 d) |
| Aphelion | 3.7664 AU (563.45 Gm) |
| Perihelion | 2.49280 AU (372.918 Gm) |
Semi-major axis | 3.12958 AU (468.179 Gm) |
| Eccentricity | 0.20347 |
Orbital period (sidereal) | 5.54 yr (2022.2 d) |
Average orbital speed | 16.64 km/s |
Mean anomaly | 32.3207° |
Mean motion | 0° 10m 40.879s / day |
| Inclination | 18.890° |
Longitude of ascending node | 143.224° |
| 318.943° | |
| Earth MOID | 1.53686 AU (229.911 Gm) |
| Jupiter MOID | 1.47086 AU (220.038 Gm) |
| TJupiter | 3.099 |
| Physical characteristics | |
| Dimensions | 106.66±2.2 km |
Synodic rotation period | 52.23 h (2.176 d) |
| 0.1135±0.0054 | |
| S (Tholen) Xk (Bus) | |
| 7.84 | |
In the Tholen classification system, it is categorized as a stony S-type asteroid, while the Bus asteroid taxonomy system lists it as an Xk asteroid. Photometric observations of this asteroid at the Goat Mountain Astronomical Research Station in Rancho Cucamonga, California during 2007 gave a light curve with a leisurely rotation period of 52.23 ± 0.05 hours.
This object is the namesake of a family of 149–778 asteroids that share similar spectral properties and orbital elements; hence they may have arisen from the same collisional event. All members have a relatively high orbital inclination.