Density maps of zero-extinction sources restricted to an area above a given column density threshold taken from the Planck-Herschel map. Kernel densities were evaluated on a grid with 1 arcmin resolution and a Gaussian kernel with 3 arcmin FWHM. Here we used the cloud to effectively block background sources to assess the population size of true foreground stars. For low column density, clearly the background contaminates the sample. Our final threshold of A_K,Herschel is a trade-off between reliable filtering and area coverage. Also note here the preferred clustering of sources towards NGC 1980 and the ONC.