IR Studies of the Circumstellar Environs of Evolved Stars

AST-0205814

PI Woodward

The interstellar medium is enriched with chemical elements synthesized in the interiors of stars and dust grains formed in their atmospheres. Stars accomplish this enrichment through mass outflows ranging in character from slow winds in post-main sequence, luminous evolved stars that operate over long time scales, to explosive events such as novae. By observing these outflows the process of chemical enrichment can be investigated. In particular IR observations will be carried out to provide abundance estimates for elements in the ejecta, such as C, N, O, Ne, Mg, Al, and Si, that can be used to assess the contributions of stellar winds to the interstellar medium. For a nova event prompt observations of sudden, transient activity at many wavelengths are required. This study will provide information about the stages of stellar evolution that are associated with mass loss, characterize the physical properties of astrophysical dust grains in circumstellar outflows, and assess the contributions that novae and luminous IR variable stars make to the grains and gas that constitute the interstellar medium.

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