Upper panel: TNG+DOLORES white (open) filter image of the field of 1RXS J180431.1−273932 with a superimposed 33-radius 90% confidence level XMM-Newton X-ray error circle. The field size is about 3′ × 3′. Lower panel: zoomed image of a 30′′ × 30′′ box centered on the XMM-Newton position. The actual counterpart (see text) is the object readily recognizable within the circle; the red giant star mentioned by Nucita et al. (2007) is the bright source just outside the circle on the right. In both panels, north is at top and east is to the left.