Structure & Evolution of Stars 1

Structure and Evolution of Stars Paul Hewett, Michaelmas 2015

SOHO image of the Sun in far-UV light

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STRUCTURE AND EVOLUTION OF STARS Michaelmas Term 2015: 24 Lectures

Schedules 2) Stellar Structure (cont.) • Hydrostatic equilibrium, Virial Theorem, Pressure • Stellar properties as a function of mass, homology • Degeneracy: Chandrasekar limit 3) Stellar Evolution and the Hertzsprung-Russell diagram • Pre-main sequence evolution, Hayashi and Henyey tracks • Post-main sequence evolution: massive stars, supernovae, neutron stars, black

holes • Post-main sequence evolution: low-mass stars, planetary nebulae, white dwarfs,

Type Ia supernovae • Initial mass function

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Schedules (continued) 4) Observational Tests and Constraints • The mass-luminosity relationship • Stellar abundances • The most massive stars and stellar winds • Supernovae

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Recommended Text Books

• Prialnik, D., An Introduction to the Theory of Stellar Structure and Evolution, Cambridge University Press, 2000, 2nd Edition 2010 – Best overall match to course

• Phillips, A.C., The Physics of Stars, Wiley, 2nd Edition,

1999 – Quite excellent on the physics of the course

• Green, S. & Jones, M., An Introduction to the Sun and

Stars, Cambridge University Press, 2004 – Gentle modern introduction to the observational aspects of the

course. Very good figures

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Recommended Text Books

• Ostlie, D.A. & Carroll, B.W., An Introduction to Modern

Stellar Astrophysics, Addison-Wesley, 1996, 2nd Edition 2013 – North American and fairly voluminous but some very good parts

• Tayler, R.J., The Stars: Their Structure and Evolution, Cambridge University Press, 1994 – Low-level overview but quite sound

• Gray, D.F., The Observation and Analysis of Stellar

Photospheres, 3rd Edition, Cambridge University Press, 2008

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Sun Mass = 2 × 1030kg Radius = 7 × 108m Lum = 3.9 × 1026W Temp = 5800K

SOHO image at 304A

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HST image of star field towards centre of the Galaxy

Luminosity? Mass? Radius? Temperature? Distance is essential

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Blackbody curves for different T

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Wide-field view of the Milky Way

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Star clusters with size << distance allow some progress. Also evidence that ∆tform << age, so stars coeval

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HIPPARCOS satellite data showing Hertzsprung-Russell diagram for stars within 150pc of the Sun

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Structure & Evolution of Stars 27 HST

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SN1987A in the LMC

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Environment of SN1987A post explosion

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Picture Credits

• Slides 8, 9, 10, 13, 14, 16, 19, 20, and 22 © from Green and Jones, CUP

• Slide 11 from Michael Brown at Princeton • Slide 18 © Ostlie and Carroll • Slide 31 from Carl Pennypacker at LBNL • SOHO, ESO and HST images as credited