Analysis of Stars Common to theIRASandHipparcosSurveys

For about 11,000 stars observed in the HIPPARCOS Survey and detected by IRASwe calculate bolometric luminosities by integrating their spectral energydistributions from the B band to far-IR wavelengths. We present an analysis ofthe dependence of dust emission on spectral type and correlations between theluminosity and dust emission for about 1000 sources with the best data(parallax error less than 30%, error in luminosity of about 50% or better).This subsample includes stars of all spectral types and is dominated by K and Mgiants. We use the IRAS [25]-[12] color to select stars with emission fromcircumstellar dust and show that they are found throughout theHertzsprung-Russell diagram, including on the main sequence. Clear evidence isfound that M giants with dust emission have luminosities about 3 times larger(about 3000 Lsun) than their counterparts without dust, and that mass loss onthe asymptotic giant branch for both M and C stars requires a minimumluminosity of order 2000 Lsun. Above this threshold the mass-loss rate seems tobe independent of, or only weakly dependent on, luminosity. We also show thatthe mass-loss rate for these stars is larger than the core mass growth rate,indicating that their evolution is dominated by mass loss.Comment: Accepted to ApJ, 14 pages, 5 figure