  We report in plane magnetization measurements on Nb/Co bilayers using a thin
superconductor Nb$\sim25$ nm and a thick ferromagnet Co$\sim40-55$ nm where
Bloch Domain Walls (BDW) are energetically favorable. Here sharp drops in the
magnetization are explained as direct consequence of BDW stray fields that
induce vortices in the out of plane direction. These are generated at small
fields around the coercive field of the ferromagnet and removed at large fields
of the order of $H_{c2}$. These two well distinctive magnetic states of the
superconductor, with or without out of plane vortices, is the same mechanism
used to explain the drops in critical currents reported in [E. J. Pati$\~{n}$o
et. al., The European Physical Journal B 68, 73 (2009)]
