| A three-dimensional model of 160 Una based on its light curve. | |
| Discovery | |
|---|---|
| Discovered by | C. H. F. Peters |
| Discovery date | 20 February 1876 |
| Designations | |
| (160) Una | |
| Pronunciation | /ˈjuːnə/ [1] |
| Main belt | |
| Orbital characteristics [2] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 118.30 yr (43209 d) |
| Aphelion | 2.90877 AU (435.146 Gm) |
| Perihelion | 2.54727 AU (381.066 Gm) |
| 2.72802 AU (408.106 Gm) | |
| Eccentricity | 0.066257 |
| 4.51 yr (1645.8 d) | |
Average orbital speed | 18.01 km/s |
| 144.472° | |
| 0° 13m 7.471s / day | |
| Inclination | 3.82512° |
| 8.60989° | |
| 52.8418° | |
| Earth MOID | 1.56031 AU (233.419 Gm) |
| Jupiter MOID | 2.30107 AU (344.235 Gm) |
| TJupiter | 3.349 |
| Physical characteristics | |
| Dimensions | 81.24±2.1 km |
| Mass | 5.6×1017 kg (assumed) |
Mean density | 2.0? g/cm3 |
Equatorial surface gravity | 0.0227 m/s2 |
Equatorial escape velocity | 0.0429 km/s |
| 11.033 h (0.4597 d) [2] 0.234 d (5.61 h) [3] [4] | |
| 0.0625±0.003 [2] 0.063 [5] | |
| Temperature | ~170 K |
| C [6] | |
| 9.08, [2] 8.95 [7] | |
160 Una is a fairly large and dark, primitive main belt asteroid that was discovered by German-American astronomer C. H. F. Peters on February 20, 1876, in Clinton, New York. [8] It is named after a character in Edmund Spenser's epic poem The Faerie Queene (1590). This minor planet is orbiting the Sun at a distance of 2.73 AU with an eccentricity of 0.07. The orbital plane is inclined at an angle of 3.83° to the plane of the ecliptic. [2]
In the Tholen classification system it is categorized as a CX-type, while the Bus asteroid taxonomy system lists it as an Xk asteroid. [9] Photometric observations of this asteroid made at the Torino Observatory in Italy during 1990–1991 were used to determine a synodic rotation period of 5.61 ± 0.01 hours. [3] It has an estimated diameter of about 81 km.