Optical DSS Red image (left) of the NGC 1333 clump compared to the Herschel-Planck total column density (centre) and dust effective temperature (right) maps (Zari et al. 2016). Offsets are referred to the map centre with coordinates in radio projection. The position of the two B-type stars (solid white stars), as well as all the Class 0/I protostars (solid black stars) and Class Flat/II/III objects (solid black squares) identified by Rebull (2015), are indicated in the first subpanel. The black contours correspond to extinction values of A_V = 10 and 20^mag and dust effective temperatures of T_eff = 14, 16, and 18 K in their respective maps. For comparison, the area covered by our IRAM 30 m observations is indicated by a dashed line in all plots (see also Fig. 5).