is a trans-Neptunian object (TNO) with an absolute magnitude of 4.38. It is in a 2:3 orbital resonance with Neptune, making it a plutino.

History Discovery

was discovered on 21 October 2003, by astronomers Michael E. Brown, Chad Trujillo, and David L. Rabinowitz. The discovery took place at the Palomar Observatory in San Diego, California. The team found the moving object using images taken by a wide-field camera mounted on the 1.2-meter Samuel Oschin Telescope.

It was given the minor planet number 455502 on 22 February 2016.

Further observations , its orbit has been secured by 513 observations across 29 oppositions, with precovery images as far back as 27 July 1954.

Orbit and classification

orbits the Sun at a distance of 30.2–48.0 astronomical units (AU) with a semi-major axis or average orbital distance of 39.1 AU once every 244 years (for reference, Neptune's orbit is at 30.1 AU). Its orbit has a relatively high eccentricity of 0.23 and an inclination of 12.05° with respect to the ecliptic.

is classified as a plutino. is in a 2:3 resonance with Neptune, which means that when it makes two revolutions around the Sun, Neptune makes exactly three.

Physical characteristics Size and albedo

The mean diameter of is estimated to be , assuming a low albedo of .

Rotation, shape and density The object rotates very fast, with a period of about 4.13 hours. It was recognized as the fastest rotator known in the Kuiper belt after Haumea in 2009.

Given its rapid rotation, if it is in hydrostatic equilibrium (and thus a dwarf planet) it must have a density higher than . Stable Jacobi ellipsoids with an axis ratio of , as implied by its light-curve amplitude of , exist for densities in the range of . Johnston's Archive reports , in the center of that range. This would make it an outlier among similarly sized TNOs, which usually have significantly lower densities, and are thought to rarely be dwarf planets.

Composition and spectrum

In visible light, this object is neutral or slightly red in color and has a flat, featureless reflectance spectrum. has a water ice-rich composition, similar to plutinos such as and . These TNOs are often classified as "prominent water"-type or "Bowl"-type TNOs. Their near-infrared spectra have a bowl-shaped water ice absorption band at around wavelength.

Notes

References

External links

2003 UZ413 Precovery Images