The Evolution of Massive Stars as a Function of Metallicity: Closing the Loop Observationally in the Local Group

Lowell Observatory, Flagstaff AZ

Investigators

Abstract

"The Evolution of Massive Stars as a Function of Metallicity: Closing the Loop Observationally in the Local Group" AST- 0093060 Although massive stars are rare, they have an importance far beyond their scant numbers. Through action of their strong outflowing winds and their eventual explosive destruction as supernovae, they provide much of the energy input into the interstellar medium. With short lifetimes of only a few million years and high mass-loss rates, they are primary sources of heavy element enrichment in a galaxy. Dr. Massey is presently concluding a survey for red supergiant, blue supergiant and Wolf-Rayet stars in nearby galaxies of the Local Group. This project is scheduled for completion during the current calendar year. Follow-up observations are now required and, during the period covered by this new award, stars found in the survey will be observed with large telescopes to obtain spectra and photometry. It will be possible to learn how the evolution of massive stars varies with mass, age and heavy element content without the observational biases that have plagued this type of investigation in the past.