Isolda (minor planet designation: 211 Isolda) is a very large, dark main-belt asteroid. It is classified as a C-type asteroid and is probably composed of primitive carbonaceous material. The spectra of the asteroid displays evidence of aqueous alteration. It was discovered by Austrian astronomer Johann Palisa on 10 December 1879, in Pola, and named after Isolde, heroine of the legend of Tristan and Iseult. In 2001, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.78 AU. The resulting data yielded an effective diameter of . Between 2009 and 2022, 211 Isolda has been observed to occult seven stars. References External links The Asteroid Orbital Elements Database Minor Planet Discovery Circumstances Asteroid Lightcurve Data File Background asteroids Isolda Isolda C-type asteroids (Tholen) Ch-type asteroids (SMASS) 18791210