Photoelectric observations of two unusual asteroids - 1978 CA and 1978 DA

The two fast-moving asteroids 1978 CA and 1978 DA, discovered in February 1978 with the ESO Schmidt telescope at La Silla (Chile), were observed with a photoelectric photometer attached to the 1-m ESO telescope. The light curve of 1978 CA displays two fairly symmetric maxima and minima with a total amplitude of 0.8 mag in V. The synodic period of rotation found is 3 h 45 m and places 1978 CA as the third fastest rotator among all known solar objects. Concerning the minor planet 1978 DA, light variations covering one full cycle of rotation could not be monitored. Nevertheless, the rotation period exceeds 5 h, and the total amplitude is greater than 0.35 mag.