Polyxo (
minor planet designation
A formal minor-planet designation is, in its final form, a number–name combination given to a minor planet (asteroid, centaur, trans-Neptunian object and dwarf planet but not comet). Such designation always features a leading number (catalog or ...
: 308 Polyxo) is a
main-belt asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
that was discovered by
A. Borrelly on March 31, 1891, in
Marseilles
Marseille ( , , ; also spelled in English as Marseilles; oc, Marselha ) is the prefecture of the French department of Bouches-du-Rhône and capital of the Provence-Alpes-Côte d'Azur region. Situated in the camargue region of southern Franc ...
. It is orbiting the
Sun at a distance of with a low
orbital eccentricity
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values betwee ...
(ovalness) of 0.04 and a
period of . The
orbital plane is tilted at an angle of 4.36° to the
plane of the ecliptic.
308 Polyxo is classified as a rare
T-type asteroid, with a spectrum that bears some similarity to the
Tagish Lake meteorite.
[ A spectral feature at a wavelength of suggests aqueous alteration of some surface materials.][ Photometric measurements reported in 1983 give a ]rotation period
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...
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.[
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.][
]
References
External links
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{{DEFAULTSORT:Polyxo
000308
Discoveries by Alphonse Borrelly
Named minor planets
000308
000308
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