(208996) 2003 AZ84
Though elongated in shape, displays a small lightcurve amplitude due to its rotation axis being oriented nearly pole-on; the variability is mainly caused by albedo features on its surface. It is considered a very likely dwarf planet by astronomers Gonzalo Tancredi and Michael Brown. However, Will M. Grundy et al. conclude that objects such as this, in the size range of 400–1000 km, with albedos less than ≈0.2 and densities of ≈1.2 g/cm or less, have likely never compressed into fully solid bodies, let alone differentiated or collapsed into hydrostatic equilibrium, and so are highly  unlikely to be dwarf planets. Physical characteristics. The Spitzer Space Telescope has estimated its size at , while an analysis of a combination of Spitzer and Hershel data yielded a slightly higher estimate of . These results are in agreement with each other. The large size of makes it a possible dwarf planet. However, the low density that results from assuming it not to be in hydrostatic equilibrium suggests the opposite. Its mass is unknown since the satellite has not been recovered. A stellar occultation in 2010 measured a single chord of . But this is only a lower limit for the diameter  of because the chord may not have passed through the center of the body. In 2017, stellar occultations and data from its rotational lightcurve suggested that had an elongated shape, presumably due to its rapid rotation rate of 6.71 hours, similar to Haumea and Varuna. That would give approximate dimensions of 940×766×490 km, with its longest axis nearly twice as long as its polar axis. The spectra and colors of are very similar to those of Orcus, another large object in 2:3 resonance with Neptune. Both bodies have a flat featureless spectrum in the visible and moderately strong water ice  absorption bands in the near-infrared, although has a lower albedo. Both bodies also have a weak absorption band near 2.3 μm, which may be caused by ammonia hydrate or methane ice. Orbit and rotation. orbits the Sun at an average distance of 39.4 astronomical units (AU) and completes a full orbit in 247 years. It is in a 2:3 orbital resonance with Neptune; completes two orbits around the Sun for every three orbits completed by Neptune. Since it is in a 2:3 resonance with Neptune, is classified as a plutino. Its orbit is inclined to the ecliptic by 13.6  degrees. The orbit of is moderately eccentric, with an orbital eccentricity of 0.183. , is currently located from the Sun. It had approached its aphelion (furthest distance from the Sun) in 1982 and will come to its perihelion (closest distance to the Sun) in 2107. Simulations by the Deep Ecliptic Survey show that over the next 10 million years will not come closer ("q") than 31.6 AU from the Sun (it will stay farther away than Neptune). The rotation period of this minor planet was first measured by Scott Sheppard in 2003. Light curves obtained by Sheppard at the University of  Hawai'i's 2.2-meter telescope gave an ambiguous rotation period of either 6.71 or 13.42 hours, with a brightness variation of 0.14 magnitudes (). The shorter rotation period refers to the single-peaked solution, expected if the brightness variations resulted from albedo spots. The longer rotation period is for a double-peaked solution, more consistent with an elongated shape. Satellite. Using observations with the Hubble Space Telescope, the discovery of a satellite of was reported in IAUC 8812 on 22 February 2007. The object was measured with a separation of 0.22 arcsec and an apparent magnitude difference of 5.0. , attempts to  recover the satellite have failed. The unrecovered satellite is estimated to be about in diameter.