Contributing factors to flux changes in nonradial stellar pulsations

AbstractThe linearized analytic representation of observed flux changes due to nonradial pulsations is examined under conditions applicable to a variety of pulsating star types. Histograms are presented as a function ofl, documenting the relative importance of local temperature, geometry, pressure, and limb-darkening variations, which are all contributing factors to the predicted flux changes. The most favourable situation for light and colour data to assist in mode discrimination for lowl requires, amongst other things, that the geometry-related factor be significant. This is noted to occur only if theQ value of the pulsation is not grossly different from theQ value of a radial fundamental pulsation. Published light and colour data for β Cephei, 53 Persei, δ Scuti, rapidly oscillating Ap, Cepheid, and ZZ Ceti variables are compared with model predictions on an amplitude ratio versus phase difference plane $$\left( {A_{co1} /A_{\lambda _1 } ,\phi _{co1} - \phi _{\lambda _1 } } \right)$$ . With the notable exception of the rapidly oscillating Ap stars, these comparisons suggest consistency of the nonradial flux change model with other known constraints on the different variable star groups.

[1]  H. K. Hansen,et al.  TEMPERATURE VARIATIONS IN HR 6684 , 1974 .

[2]  R. S. Stobie,et al.  The effect of radial and non-radial stellar oscillations on the light, colour and velocity variations , 1979 .

[3]  M. Smith.  Pulsational mode-typing in line profile variables. III - Multimode behavior in 12 Lacertae , 1980 .

[4]  Donald W. Kurtz,et al.  Frequency analysis of the 5.65-min oscillations in the rapidly oscillating Ap star HD 134214 , 1986 .

[5]  H. Saio,et al.  Linear, nonadiabatic analysis of nonradial oscillations of massive near main sequence stars , 1980 .

[6]  R. Buta,et al.  The light variations of nonradial pulsators: theory and application to the line profile variable 53 Persei. , 1979 .

[7]  C. Hansen,et al.  The pulsation properties of DB white dwarfs - A preliminary analysis , 1983 .

[8]  D. Kurtz.  The δ Scuti variability of the high metallicity δ Del star, rho Pavonis , 1981 .

[9]  D. Kurtz.  Frequency analysis of the light variability of HD 101065, Przybylski's star , 1980 .

[10]  D. Gough.  Nonradial and nonlinear stellar pulsation , 1979, Nature.

[11]  C. Sterken,et al.  Periods in the light variation of σ Scorpii , 1984 .

[12]  D. Kurtz,et al.  A frequency analysis of the 6.8-min oscillations in the cool magnetic AP star α Cir , 1984 .

[13]  E. L. Robinson,et al.  Photometric observations of GD 358 : OB white dwarfs do pulsate. , 1982 .

[14]  S. Starrfield,et al.  Nonradial instability strips based on carbon and oxygen partial ionization in hot, evolved stars , 1984 .

[15]  R. Stobie,et al.  Frequency analysis of double-mode cepheids , 1979 .

[16]  M. Smith.  Pulsational mode-typing in line profile variables. V. Multimodes and ''moving shells'' in. nu. Eridani and other. beta. Cephei stars , 1983 .

[17]  R. Stobie,et al.  The oscillation modes of 1 Monocerotis , 1980 .

[18]  M. A. Smith,et al.  The nonradial oscillations of Spica. I - Two commensurable modes. II - A 'quasi-toroidal' mode , 1985 .

[19]  J. Lesh.  Ultraviolet photometry from the Orbiting Astronomical Observatory. XXVIII - Ultraviolet light curves for Alpha Lupi and BW Vulpeculae , 1978 .

[20]  R. Kurucz.  Model atmospheres for G, F, A, B, and O stars , 1979 .

[21]  C. Hansen,et al.  Temperatures for Hot and Pulsating DB White Dwarfs Obtained with the IUE Observatory , 1986 .

[22]  T. G. Barnes,et al.  Observational studies of Cepheids. III: Catalog of light curve parameters , 1984 .

[23]  John P. Cox,et al.  Theory of Stellar Pulsation No. 2 , 1980 .

[24]  J. Toomre.  Properties of Solar Oscillations , 1986 .

[25]  J. McGraw.  The physical properties of the ZZ Ceti stars and their pulsations. , 1979 .

[26]  R. Shobbrook.  The Beta Canis Majoris Stars 15 CMa and ξ1 CMa , 1973 .

[27]  M. Smith,et al.  Undulations of a B-type star: 53 Persei. , 1978 .

[28]  R. D. Watson.  Colour changes in mid-B star variables , 1987 .

[29]  M. Smith.  Nonradial pulsation in Iota Herculis and 10 Lacertae (1975 - 1977). , 1978 .

[30]  W. Julius.  Radial Motion in Sun-Spots , 1914 .

[31]  T. Kreidl.  Differential photometry of the δ Sct stars HR 151 and HR 239 , 1985 .

[32]  F. Wesemael.  Atmospheres for hot, high-gravity stars. II. Pure helium models , 1981 .

[33]  E. L. Robinson,et al.  Multicolor variations of the ZZ Ceti stars , 1982 .

[34]  D. Kurtz.  A Review of the Rapidly Oscillating Ap Stars , 1986 .

[35]  M. Smith,et al.  Pulsational mode-typing in line profile variables. I - Four Beta Cephei stars , 1980 .

[36]  R. D. Watson,et al.  Baade-Wesselink and related techniques for mode discrimination in nonradial stellar pulsations , 1981 .

[37]  R. Stellingwerf,et al.  Pulsation in the lower Cepheid strip. I. Linear survey. , 1979 .

[38]  D. F. Gray,et al.  The Observation and Analysis of Stellar Photospheres , 2021 .

[39]  D. Kurtz.  Rapidly Oscillating Ap Stars , 1982 .

[40]  D. Gough.  Stellar structure: Beginnings of asteroseismology , 1985, Nature.

[41]  A. Ferro.  Physical parameters and pulsational mode of short-period small-amplitude Cepheids , 1984 .

[42]  A. Cox,et al.  Cepheid masses from observations and pulsation theory. , 1979 .

[43]  H. Bond,et al.  Two new extremely hot pulsating white dwarfs , 1984 .

[44]  R. Watson,et al.  Observational characteristics of simple radial and non-radial β Cephei models , 1977 .

[45]  J. Bregman,et al.  Period--luminosity--color relations and pulsation modes of pulsating variable stars , 1975 .

[46]  J. Christensen-Dalsgaard,et al.  Theory of Stellar Pulsation , 1982 .

[47]  P. W. Hill,et al.  Photometric and spectroscopic evidence for non-radial pulsation in the extreme helium star BD – 9° 4395 , 1985 .

[48]  R. Shobbrook.  New radial pulsation constants for the β Cephei variables , 1985 .