308 Polyxo

308 Polyxo
Orbital diagram
Discovery
Discovered byA. Borrelly
Discovery date31 March 1891
Designations
(308) Polyxo
Pronunciation/pəˈlɪksoʊ/[1]
Named after
Πολυξώ Polyxō
Main belt
AdjectivesPolyxoian /pɒlɪkˈsoʊiən/
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc124.63 yr (45,521 d)
Aphelion2.860 AU (427.8 Gm)
Perihelion2.640 AU (394.9 Gm)
2.750 AU (411.4 Gm)
Eccentricity0.040003
4.56 yr (1,665.5 d)
70.4189°
0° 12m 58.158s / day
Inclination4.36141°
181.727°
115.501°
Physical characteristics
Dimensions140.69±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 a main-belt asteroid that was discovered by A. Borrelly on 31 March 1891, in Marseilles. It is orbiting the Sun at a distance of 2.75 AU with a low orbital eccentricity (ovalness) of 0.04 and a period of 4.56 yr. The orbital plane is tilted at an angle of 4.36° to the plane of the ecliptic.[2]

308 Polyxo is classified as a rare T-type asteroid, with a spectrum that bears some similarity to the Tagish Lake meteorite.[6] A spectral feature at a wavelength of 3.0 μm suggests aqueous alteration of some surface materials.[4] Photometric measurements reported in 1983 give a rotation period of 12.03 hours and a brightness variation of 0.20 in magnitude. The adaptive optics instrument at the W. 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 resulting chords provided cross-section diameter estimates of 144.4 and 117.1 km, respectively.[7]

  1. ^ Cite error: The named reference Webster1884 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference jpldata was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Marchis2006 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Dotto_et_al_2004 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Dotto_et_al_2002 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Hiroi_Hasegawa_2003 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Shevchenko_Tedesco_2006 was invoked but never defined (see the help page).