Classical Cepheid pulsations

Conference · Sat Dec 01 04:00:00 EST 1990 · Annals of the New York Academy of Sciences; (USA)

OSTI ID:5760015

Moskalik, P; Buchler, J R; Kovacs, G ^[1]

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1. Florida Univ., Gainesville (USA)

Theoretical models of classical Cepheid variable stars are examined by means of test computations focusing on (1) the systematic period change known as the Hertzsprung or bump progression and (2) the hypothesis (Simon and Schmidt, 1976) that (1) is due to a 2:1 resonance between the fundamental mode and the second overtone. One-parameter families or sequences of models are calculated which represent 'snapshots' of pulsational behavior at different points on the Cepheid evolutionary tracks, and a remarkable uniformity is found when the Fourier coefficients for sequences with moderate luminosity/mass ratios are plottted against the linear period ratio. The complete disappearance of this uniformity when the coefficients are plotted against the pulsation period itself is shown to be consistent with (2). The description of these phenomena with amplitude equations is explained, and expressions for estimating the width of the instability strip are derived. 32 refs.

• OSTI ID: 5760015
• Report Number(s): CONF-8910308--
• Conference Information: Journal Name: Annals of the New York Academy of Sciences; (USA) Journal Volume: 617
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLITUDES
ASTROPHYSICS
CEPHEIDS
LUMINOSITY
MASS
MATHEMATICAL MODELS
OPTICAL PROPERTIES
OSCILLATIONS
PHYSICAL PROPERTIES
PULSATING VARIABLE STARS
PULSATIONS
RADIAL VELOCITY
STAR EVOLUTION
STAR MODELS
STARS
STELLAR RADIATION
VARIABLE STARS
VELOCITY