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Z. Ivezic (Princeton University), T.G. Knauer (University of Kentucky), G.R. Knapp (Princeton University)
For about 12,000 sources observed in both the IRAS and HIPPARCOS Surveys we calculate bolometric luminosities from the integrated spectral energy distributions from the UV to far-IR wavelengths and the HIPPARCOS parallaxes. We present an analysis of the spectral properties, and correlations between the luminosity and dust emission for about 2,000 sources with the best data (error in luminosity of less than 50%). We use the IRAS [25]-[12] color to select sources with dust emission and show that they are found throughout the Hertzsprung-Russell diagram, including pre-main-sequence, main sequence, and post-main-sequence objects. We find clear evidence that M and N stars with dust emission have luminosities 3-4 times larger than their counterparts without dust, and find a minimum threshold luminosity of about 2000 Lo for stars to have dust, in agreement with models for radiatively driven winds. Once this threshold is achieved, the amount of circumstellar dust is independent of the stellar luminosity.
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