A Precessing Disk in OJ 287?

Sillanpaa et al. have demonstrated that the active galactic nucleus OJ 287 has intensity peaks that recur within a period of about 12 yr. I suggest that this is the result of the sweeping of a precessing relativistic beam across our line of sight. In analogy to Hercules X-1 and SS 433, precession is attributed to the torque exerted by a companion mass on an accretion disk. Secondary maxima observed 1.2 yr after two of these peaks may be evidence of nodding motion.