Brightness variation of the asteroid (35690) 1999 CT21

The asteroid (35690) 1999 CT21 was incidentally recorded on 29 and 30 July 2000 UT during the observations of the globular cluster M22. These data have allowed determination of the synodic rotation period to be 9.06 ± 0.02 hours. On 29 July 2000 the reduced V magnitude, the amplitude of the light variation and color index B-V were 14.82 ± 0.01, 0.60 ± 0.02 and 0.7 ± 0.1 mag, respectively. Dimensions and the biaxial ellipsoid models of this asteroid have been obtained for two assumed taxonomic classes (C and S).