Dipole Straylight Contamination and Low Multipoles

Kinematic dipole signal originates from the motion of the Sun with respect to the CMB rest frame. It is a remarkable signal, two orders of magnitude larger than the observed pattern of CMB anisotropies. Therefore the dipole subtraction from the main beam is of primary importance. But what happens to the dipole signal entering the main spillover (i.e. the most relevant far antenna pattern feature, responsible for the bulk of the straylight effect)? We present here an analytical and statistical study of this systematic effect for a spinning space-mission like PLANCK ∗.