==================================================================== ==================================================================== We propose to use PHOT to measure the 25 mu to 200 mu emission of a remarkable, new protostellar clump recently discovered by us in the Taurus molecular cloud with the IRAM 30m telescope at 1.3 mm. There is no IRAS source at this position. Deep ISOCAM images at 7.75 mu and 15 mu show no mid-IR source either. However, the clump is associated with a weak 3.6cm VLA radio source and a collimated CO outflow. Furthermore, millimeter line observations provide evidence that the clump is collapsing. It is thus likely a young accreting (Class 0) protostar similar to, but less massive and less evolved than, VLA1623 or L1527. The proposed PHOT observations will give unique constraints on the bolometric luminosity and temperature of this source, which are currently poorly known. This should allow us to determine whether the clump is indeed a Class 0 protostar or an isothermal protostar with no central YSO.