Young stellar clusters: From ISO to Herschel

The, studies of young stellar clusters with ISO are introduced as a starting point for potential studies with the Herschel Space Observatory. The. higher spatial resolution at longer wavelengths is identified as the major strength of Herschel for studies of star forming regions. The likely advances of the future SIRTF studies are outlined and emphasis is given to areas where Herschel is likely to make major advances after the SIRTF results. In the interpretation of the luminosity function of young stellar clusters the most interesting targets are the very youngest star forming regions where. the embedded population dominates the number counts. These studies allow addressing the issues of accretion processes in protostars. For somewhat older clusters with star formation ages of the order of a few million years, the most interesting aspect is to examine the disk dispersal time scales. The open issue for Herschel will be the question of cool disk dispersal in view of the very rapid inner disk dispersal observed in the near infrared. SIRTF will make a significant contribution to many other studies of star formation and disk dispersal processes. Therefore a Herschel key programme in these areas can only be fine tuned after the SIRTF results have been made available.