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Title: l = 0, 1, 2, and 3 pulsation constants for evolutionary models of delta Scuti stars

Journal Article · · Astrophys. J.; (United States)
DOI:https://doi.org/10.1086/159278· OSTI ID:5730355

Evolutionary sequences at M/M/sub sun/ = 1.5, 2.0, and 2.5 were calculated with a version of the Eggleton stellar evolution code for an initial composition X = 0.70, Z = 0.02. From these sequences 14 models spanning the lower part of the Cepheid instability strip were selected for pulsation calculations. All the linear adiabatic m-degenerate eigenvalues with l< or =3 for pulsation constants Q( = P(/)/sup 1/2/) in the range 0/sup d/.0096< or =Q< or =0/sup d/.067 were obtained with a modified version of Dziembowski's second pulsation code, and our code uses a variant of the Cowling approximation for the nonradial modes. Four hundred and eighty-nine Q-values for 35 modes of types F--7H and g/sub 2/--p/sub 7/ are presented. Interpolation formulae are provided which predict the model masses, radii, and luminosities from the model periods and temperatures, with worst case errors of 4.4, 2.4, and 1.2% in M, L, and R, respectively, when using any of the radial mode or some of the nonradial f- and p-mode results. These formulae were applied to a selection of eight delta Scuti and three AI Velorum type variables to yield masses and luminosities in the ranges 1.68< or =M/M/sub sun/< or =2.56 and 15.4< or =L/L/sub sun/< or =78.0, respectively. If our pulsation constants are relevant, then the primary uncertainties in these results follow from the uncertainties in the effective temperatures for these stars, which are here discussed.

Research Organization:
Steward Observatory, University of Arizona, and Theoretical Division, Los Alamos Scientific Laboratory, University of California
OSTI ID:
5730355
Journal Information:
Astrophys. J.; (United States), Vol. 249:1
Country of Publication:
United States
Language:
English