Planetary Nebulae

TL;DR

Planetary nebulae are glowing shells of ionized gas formed from dying stars, serving as key laboratories for astrophysics, astrochemistry, and astromineralogy research.

Contribution

This chapter reviews the formation, structure, and scientific significance of planetary nebulae, highlighting their role in advancing multiple fields of astronomy.

Findings

Planetary nebulae reveal complex ionization and chemical processes.

They serve as laboratories for studying stellar evolution and chemical enrichment.

Their diverse morphologies impact understanding of stellar mass loss.

Abstract

Planetary nebulae are formed by the matter ejected by low-to-intermediate mass stars (~0.8-8 times the mass of the Sun) towards the end of their lives. As hydrogen and then helium fuel sources run out, stars expand. During these giant phases stars also lose sizable amounts of mass. During the second giant phase, after the exhaustion of core helium, the mass loss is so great that stars lose a large fraction of their mass (50 - 90%), leaving behind a small, hot core, known as a white dwarf, surrounded by a nebula. Planetary nebulae are the result of many processes that shape and alter their ionization structure and chemical composition. The resulting nebula, illuminated by the ultraviolet-rich spectrum of the remnant very hot stellar core, is a spectacle of beauty and science. In this chapter, we show that these objects are invaluable laboratories for astrophysics, astrochemistry, and astromineralogy studies, with impact in many areas of Astronomy.