45″×45″DES, GTC/OSIRIS, and VLT/FORS2 z-band images of the fields of all the targets with conventional orientation (up is north and left is east). The blue dots are the object positions at the previous epochs published by other authors (Table A.1), and the red ellipses are the projected positions where those targets are supposed to be on the dates of the observations according to their proper motions from the literature in Table A.1. Parallax effects are negligible. The two semi-axes of the ellipses show the errors of projected position in RA and Dec, based on proper motion uncertainties and the time difference between the two epochs. All the objects have been detected. The correct positions of W0156 and W0711 are indicated with the red arrows.