A photometric study in 2001 was unable to find a definite period of rotation. Infrared observations of Chariklo indicate water ice on the surface. Mike Brown's website lists it as a possible dwarf planet with a measured diameter of 258 km.
If one knows the absolute magnitude (H) and the albedo of an object, one can estimate the size. But since centaurs are icy comet-like bodies that may outgas, it is very difficult to estimate their albedos. It is also likely that the albedos of some centaurs vary with time and activity levels.
With an absolute magnitude (H) of 6.4 and an albedo of 0.06, Chariklo is currently the largest known centaur with an estimated diameter of 258 km.2060 Chiron (230 km / H=6.5 / albedo=0.07) is likely a close second. The lost centaur 1995 SN55 (H=6.0) may even be larger, with an estimated diameter very close to 300 km.
Chariklo lies within 0.09 AU of the 4:3 resonance of Uranus.
Centaurs are believed to have originated from the Kuiper belt and are in dynamically unstable orbits that will lead either to ejection from the Solar System, an impact with a planet or the Sun, or evolution into a short-period comet.
The orbit of Chariklo is more stable than Nessus, Chiron, and Pholus. Chariklo lies within 0.09 AU of the 4:3 resonance of Uranus and is estimated to have a long orbital half-life of about 10.3 Myr. Orbital simulations of twenty clones of Chariklo suggest that Chariklo will not start to regularly come within 3AU (450Gm) of Uranus for about thirty thousand years.
^ abcdeJohn Stansberry, Will Grundy, Mike Brown, Dale Cruikshank, John Spencer, David Trilling, Jean-Luc Margot (2007). "Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope". arXiv:astro-ph/0702538 [astro-ph].