  We theoretically study the motion of a rigid dimer of self-propelling Janus
particles. In a simple kinetic approach without hydrodynamic interactions, the
dimer moves on a helical trajectory and, at the same time, it rotates about its
center of mass. Inclusion of the effects of mutual advection using
superposition approximation does not alter the qualitative features of the
motion but merely changes the parameters of the trajectory and the angular
velocity.
