CCD photometry of asteroids 276 Adelheid, 1490 Limpopo, and 2221 Chilton from the Universidad de Monterrey Observatory

CCD photometry of asteroids 276 Adelheid, 1490 Limpopo, and 2221 Chilton obtained at the Universidad de Monterrey Observatory during August and September 2005 is reported. A synodic rotation period of 6.315±0.005 hours and an amplitude of 0.17±0.03 magnitudes is confirmed for Adelheid from five nights of observations. The resulting synodic rotation period and amplitude for Limpopo is 6.426±0.003 hours and 0.16±0.03 magnitudes from three nights of observations. Chilton was observed on four nights and exhibits a synodic rotation period of 7.445±0.015 hours and an amplitude of 0.20±0.05 magnitudes, though the period is uncertain due to the faintness of the asteroid in the images. Another possible solution for the rotation period of Chilton is 8.63±0.02 hours.