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Oscillations of Long-Period Variables

Published online by Cambridge University Press:  08 February 2017

D.R. Xiong ,
L. Deng  and
Q. L. Cheng
D.R. Xiong
Affiliation:
Purple Mountain Observatory, Academia Sinica, Nanjing 210008, P.R. China
L. Deng
Affiliation:
Beijing Astronomical Observatory, Beijing 100080, P.R. China
Q. L. Cheng
Affiliation:
Purple Mountain Observatory, Nanjing 210008, P.R. China

Abstract

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We have performed a linear pulsational stability survey of long period variable models. The dynamic and thermodynamic couplings between convection and oscillations are treated by using a statistical theory of nonlocal and time-dependent convection. The results show that the fundamental and all the low overtones are always pulsationally unstable for the low-temperature models when the coupling between convection and oscillations is ignored. When the coupling is considered, there is indeed a “Mira” pulsationally instability region outside of the Cepheid instability strip on the H-R diagram. The coolest models near the Hayashi track are pulsationally stable. Towards high temperature the fundamental mode first becomes unstable, and then the first overtone. Some of the 2nd −4th overtones may become unstable for the hotter models. All the modes higher than 4th (n > 4) are pulsationally stable. The position and the width of such an instability region on the H-R diagram critically depends on the mass, luminosity and metal abundance of the star.

Type
VI. Asteroseismology II
Information
Symposium - International Astronomical Union , Volume 185: New Eyes to See Inside the Sun and Stars , 1998 , pp. 399 - 400
Copyright
Copyright © Kluwer 1998 

References

Hughes, S.M.G. & Wood, P.R., (1990), (1990), AJ, 99, 784 Google Scholar
Glass, I.S., Catchpole, R.M., Feast, M.W., Whitelock, P.A. & Reid, I.N., (1987), in In the Late Stages of Stellar Evolution, eds. Kwok, S. and Pottasch, S. R., (Reidel), p. 51 Google Scholar
Wood, P.R. (1990a), in From Miras to Planetary Nubulae ed. Mennesier, M.O. and Omont, A. (Editions Frontieres), p. 67 Google Scholar
Wood, P.R. (1990b), in A.S.P. Conf. Ser. Vol 11, eds. Cacciari, C. and Clementini, G. (San Francisco, CA), p355 Google Scholar
Xiong, D.R., Deng, L. & Cheng, Q.L. (1997a), submitted to ApJ.Google Scholar
Xiong, D.R., Cheng, Q.L. & Deng, L. (1997b), submitted to ApJ.Google Scholar