\psset{linewidth=0.4\pslinewidth,PointSymbol=none, PointName=none}
\pstGeonode[PosAngle=-90, PointSymbol={none,*,none}, PointName={none,default,none}]
  {O}(4;132){A}(5,0){O'}
\pstCircleOA{O}{O'}
\multido{\n=5+5}{72}{%
  \pstGeonode(5;\n){M_\n}
  \pstMediatorAB[nodesep=-15,linecolor=magenta]{A}{M_\n}{I}{J}} % fin multido