 Orbital diagram | |
| Discovery | |
|---|---|
| Discovered by | Alphonse Borrelly |
| Discovery date | 31 March 1891 |
| Designations | |
| (308) Polyxo | |
| Pronunciation | /pəˈlɪksoʊ/[1] |
Named after | ΠολυξώPolyxō |
| Main belt | |
| Adjectives | Polyxoian/pɒlɪkˈsoʊiən/ |
| Orbital characteristics[2] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 124.63 yr (45,521 d) |
| Aphelion | 2.860 AU (427.8 Gm) |
| Perihelion | 2.640 AU (394.9 Gm) |
| 2.750 AU (411.4 Gm) | |
| Eccentricity | 0.040003 |
| 4.56 yr (1,665.5 d) | |
| 70.4189° | |
| 0° 12m 58.158s / day | |
| Inclination | 4.36141° |
| 181.727° | |
| 115.501° | |
| Physical characteristics | |
| Dimensions | 140.69±3.8 km[2] 130 km[3] |
| 12.031 ± 0.009 h (0.50129 ± 0.00038 d)[4] | |
| 0.043±0.002[5] | |
| T[4] (Tholen) | |
| 8.17 | |
308 Polyxo is amain-beltasteroid that was discovered byAlphonse Borrelly on 31 March 1891, inMarseille. It is orbiting theSun at a distance of2.75 AU with a loworbital eccentricity (ovalness) of 0.04 and aperiod of 4.56 yr. Theorbital plane is tilted at an angle of 4.36° to theplane of the ecliptic.[2]
308 Polyxo is classified as a rareT-type asteroid, with a spectrum that bears some similarity to theTagish Lake meteorite.[6] A spectral feature at a wavelength of3.0 μm suggests aqueous alteration of some surface materials.[4]Photometric measurements reported in 1983 give arotation period of 12.03 hours and a brightness variation of 0.20 inmagnitude. Theadaptive optics instrument at theW. M. Keck Observatory shows an oblate object with a diameter of 130 km. The size ratio between the major and minor axes is 1.26 ± 0.11.[3]Light curves for this object suggests it has a very irregular shape.[4]
Stellar occultation events were observed for this asteroid during 2000 and 2004. The resultingchords provided cross-section diameter estimates of 144.4 and 117.1 km, respectively.[7]
