We use our Monte Carlo radiative transfer code to study non-embedded prestellar cores and cores that are embedded at the centre of a molecular cloud .
Our study indicates that the temperature inside embedded cores is lower than in isolated non-embedded cores , and generally less than 12 K , even when the cores are surrounded by an ambient cloud of small visual extinction ( A _ { V } \sim 5 ) .
Our study shows that the best wavelength region to observe embedded cores is between 400 and 500 \mu m , where the core is quite distinct from the background .
We also predict that very sensitive observations ( \sim 1 - 3 MJy { sr ^ { -1 } } ) at 170-200 \mu m can be used to estimate how deeply a core is embedded in its parent molecular cloud .
Finally , we present preliminary results of asymmetric models of non-embedded cores .