Evolved Mass-Losing Stars in the Milky Way: Numbers, Distribution, Mass-Loss Rates, Lifetimes, Birthrates, and Precursors.

We have used the IRAS Point Source Catalog to study the distribution, total number, lifetimes, birthrates, and mass-loss rates of highly-evolved carbon-and oxygen-rich stars in the Milky Way. For our sample of infrared-selected carbon stars we find a local surface density of sigma = 5.2 kpc sup (-2), implying sigma = 31 kpc sup (-2) for all carbon stars. The infrared- selected oxygen stars in our sample have sigma = 47 kpc sup (-2). We estimate the total number of dusty, mass-losing oxygen stars to be about 48,000 in the Milky Way, while the total number of carbon stars is around 22,000[R sub G /15]sup 2, where R sub G is the radius of the Galaxy in kpc.