The positions (black and white dots) of the 89 mainly B-type members of Upp Sco are shown (with HD numbers) on top of a 100 μm infrared dust map of this region (Schlegel et al. 1998). The north-east arrows are 3° in length. The ρ Oph cloud can be identified by the bright filamentary emission located just left to the center of the figure. The dust emission (on a logarithmic grey scale) is proportional to the reddening E_(B−V) of sightlines penetrating these clouds; the lowest intensities correspond to E_(B−V)  ~ 0.02 mag (black) and highest intensities to  ≥ 2 mag (white). The well-known targets σ Sco (HD 147165, in the ρ Oph cloud) and ζ Oph (HD 149757, top left) are included in our study.