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SUMMARY:Stellar pulsation: excitation\, diagnosis and seismology - Simon J
 effery\, Armagh Observatory and Planetarium
DTSTART:20190225T140000Z
DTEND:20190225T150000Z
UID:TALK120334@talks.cam.ac.uk
CONTACT:Cleo Loi
DESCRIPTION:Pulsations in stars across the Hertzsprung-Russell diagram are
  caused by the excitation of normal modes of oscillation by various means.
  The classical opacity (or kappa-gamma)  mechanism responsible for the wel
 l-known Cepheid variables relies on peaks in the internal opacity - temper
 ature distribution in a star. Starting from both linear and non-linear mod
 els\, we will discuss the internal stellar chemistries that lead such peak
 s to produce pulsations in many classes of evolved star. We will explore o
 ne star in particular\, V652 Her\, where high-precision observations of la
 rge amplitude pulsations can be directly compared with hydrodynamic models
 \, and we shall demonstrate how pulsations studies can reveal a star’s h
 idden past.
LOCATION:MR14\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
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