Using ISO-ISOPHOT we carried out a survey of almost 150 stars to search for evidence of emission from dust orbiting young main sequence stars , both in clusters and isolated systems .
Over half of the detections are new examples of dusty stellar systems , and demonstrate that such dust can be detected around numerous stars older than a few \times 10 ^ { 6 } years .
Fluxes at 60 \micron and either 90 or 100 \micron for the new excess sources together with improved fluxes for a number of IRAS-identified sources are presented .
Analysis of the excess luminosity relative to the stellar photosphere shows a systematic decline of this excess with stellar age consistent with a power law index of -2 .