Science with an ngVLA: Evolved Stars

TL;DR

This paper discusses how the ngVLA will advance understanding of the late evolutionary stages of low-to-intermediate mass stars, focusing on observational techniques and expected scientific contributions.

Contribution

It outlines the specific observational capabilities of the ngVLA for studying evolved stars and their circumstellar environments, highlighting new insights into stellar evolution.

Findings

Enhanced continuum imaging of radio photospheres.

Detailed studies of circumstellar envelopes in thermal and nonthermal lines.

Insights into the transition from AGB stars to planetary nebulae.

Abstract

This chapter reviews some of the expected contributions of the ngVLA to the understanding of the late evolutionary stages of low-to-intermediate mass stars, including asymptotic giant branch (AGB) stars, post-AGB stars, and pre-planetary nebulae. Such objects represent the ultimate fate of stars like the Sun, and the stellar matter they lose to their immediate vicinity contributes significantly to the chemical enrichment of galaxies. Topics addressed in this chapter include continuum imaging of radio photospheres, studies of circumstellar envelopes in both thermal and nonthermal lines, and the investigation of the transition stages from the AGB to planetary nebulae using radio wavelength diagnostics. The authors gratefully acknowledge contributions to the content of this chapter from members of the evolved star community.