The evolutionary state of the cool hypergiants episodic mass loss, convective activity and magnetic fields

Roberta M Humphreys

Research output: Contribution to journalArticle

Abstract

The evolved cool stars near the empirical upper luminosity boundary in the HR Diagram all show evidence for considerable instability perhaps due to their proximity to this stability limit and/or their evolutionary state. Recent high resolution imaging and spectroscopy of several of these stars have revealed a subset characterized by complex ejecta and evidence for episodic mass loss driven by convective activity and magnetic fields. This group includes famous stars such as the red supergiants VY CMa, NML Cyg and the post RSG IRC +10420. I will review the observational evidence and discuss the implications for the final stages of these evolved stars, their mass loss mechanism, and evolutionary state.

Original languageEnglish (US)
Pages (from-to)111-118
Number of pages8
JournalProceedings of the International Astronomical Union
Volume3
Issue numberS250
DOIs
StatePublished - Dec 1 2007

Fingerprint

Stars
Magnetic fields
magnetic field
stars
ejecta
magnetic fields
Hertzsprung-Russell diagram
cool stars
diagram
spectroscopy
set theory
proximity
luminosity
Luminance
high resolution
Spectroscopy
Imaging techniques
loss

Keywords

  • Stars: evolution
  • Stars: magnetic fields
  • Stars: mass loss

Cite this

The evolutionary state of the cool hypergiants episodic mass loss, convective activity and magnetic fields. / Humphreys, Roberta M.

In: Proceedings of the International Astronomical Union, Vol. 3, No. S250, 01.12.2007, p. 111-118.

Research output: Contribution to journalArticle

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