Photometric observations of 1978CA and 1978DA

UBV photometric observations of the earth-crossing asteroid 1978 CA and the Mars-crosser 1978 DA are reported. Light curves are plotted which indicate that 1978 CA has a rotation period of approximately 3 hr 45 min and that 1978 DA rotates about its axis much more slowly than 1978 CA. The following color indices are determined: (B-V) of approximately 0.90 and (U-B) of about 0.48 for 1978 CA and (B-V) = 0.83 and (U-B) = 0.41 for 1978 DA. A model that may explain the observed smooth and nearly symmetric light curve of 1978 CA is briefly discussed.