Evolved Stars and their Circumstellar Environments

When low- and intermediate-mass stars exhaust their nuclear fuel in their cores, they expand and enter the giant branch in the HR diagram. Eventually, some also ascend the asymptotic giant branch (AGB), potentially leading to planetary nebulae formation.  AGB stars dominate the enrichment of several of the pre-biotic elements (e.g. C, N) and are therefore critical to our understanding of Galactic chemical evolution.  The evolution of supergiants can  provide information on open cluster evolution and star formation history. Generally speaking, evolved stellar objects also provide unique laboratories for the study of molecule and dust formation and matter-radiation interactions in highly irradiated environments.

This workshop will explore how theoretical and observational studies of evolved stellar objects can contribute to the understanding of a critical part of stellar evolution. Because giant stars tend to be cool with significant circumstellar, often dusty, envelopes, red [super] giants, AGB stars, planetary nebulae, and related objects are ideally suited for studies at infrared and [sub]mm wavelengths.  We will encourage discussions on synergies between infrared observations and other techniques, and how laboratory work can contribute to the advancement of the field.

Addressed topics will include:

- Gas chemistry in different regions of stellar objects / different star types

- Connection to the ISM

- Elemental enrichment

- Dust formation theory

- Dust observations: chemical composition and polarimetric properties

- Temporal evolution

- Related Laboratory Experimental studies


14 – 17 December 2021