Size determination of the Centaur Chariklo from millimeter-wavelength   bolometer observations
  Using the Max-Planck Millimeter Bolometer Array (MAMBO) at the IRAM 30m telescope we detected emission at 250 GHz from the Centaur Chariklo (1997 CU26). The observed continuum flux density implies a photometric diameter of 273 km. The resulting geometric albedo is 0.055, somewhat higher than expected from a comparison with most of the other few Centaurs and cometary nuclei for which such data are available. 
W. J. Altenhoff, K. M. Menten and F. Bertoldi (Max-Planck-Institut   fuer Radioastronomie)