161989 Cacus
Shape model of Cacus from its lightcurve | |
| Discovery | |
|---|---|
| Discovered by | H.-E. Schuster |
| Discovery site | La Silla Obs. |
| Discovery date | 8 February 1978 |
| Designations | |
| (161989) Cacus | |
Named after | Cacus (Roman mythology) |
| 1978 CA | |
| Apollo · NEO · PHA | |
| Orbital characteristics | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 38.59 yr (14,096 days) |
| Aphelion | 1.3634 AU |
| Perihelion | 0.8828 AU |
| 1.1231 AU | |
| Eccentricity | 0.2140 |
| 1.19 yr (435 days) | |
| 345.40° | |
| 0° 49m 41.16s / day | |
| Inclination | 26.060° |
| 161.24° | |
| 102.16° | |
| Earth MOID | 0.0152 AU · 5.9 LD |
| Physical characteristics | |
| 0.64±0.02 km 1.126±0.073 km 1.86 km 1.9 km | |
| 3.7538±0.0019 h 3.756 h 3.761 h 3.77±0.11 h | |
| 0.09 0.119 (derived) 0.199±0.052 0.46±0.09 | |
| Tholen = S · Q B–V = 0.910 U–B = 0.484 | |
| 16.58 · 17.1 · 17.2 · 17.32 · 17.43 | |
161989 Cacus (prov. designation: 1978 CA) is a stony asteroid, classified as near-Earth object and a potentially hazardous asteroid of the Apollo group, approximately 1 kilometer in diameter. It was discovered on 8 February 1978, by German astronomer Hans-Emil Schuster at ESO's La Silla Observatory in northern Chile. Its orbit is confined between Venus and Mars.
This minor planet was named from Roman mythology, after Cacus, a fire-breathing monster, which was killed by Hercules. The official naming citation was published by the Minor Planet Center on 24 November 2007 (M.P.C. 61270).
| Date | JPL SBDB nominal geocentric distance |
uncertainty region (3-sigma) |
|---|---|---|
| 1941-09-02 | 2418754 km | ± 6 km |
| 2022-09-01 | 8607710 km | ± 21 km |