INFRARED-EMISSION FROM GLOBULAR-CLUSTERS - LIMITS ON STELLAR MASS-LOSS AND INTERSTELLAR DUST

The IRAS Faint Source Catalog was searched for infrared emission from 84 globular clusters above \b\ = 10 degrees. Emission was detected fro m 19 clusters which can plausibly be attributed to photospheric radiat ion from the ensemble of cool evolved stars. The 12 mu m flux densitie s show no measurable excess over the blackbody values, setting limits on the amount of circumstellar dust and hence on the stellar mass-loss rates of typically less than a few times 10(-8) M(.) yr(-1) per star. The IRAS data also set very low limits on interstellar dust in globul ar clusters. Together, these observations suggest that the rate of mas s injection by globular cluster stars is less than or equal to 10(-7) M(.) yr(-1) for the whole cluster. The only cluster for which emission is detected at long wavelengths (60 mu m or 100 mu m) is M15. The 60 mu m emission is positionally coincident with a small dark obscuring c loud and not with the planetary nebula K648.