Pushing the ground-based limit: 14-μmag photometric precision with the definitive Whole Earth Telescope asteroseismic data set for the rapidly oscillating Ap star HR 1217

HR 1217 is one of the best-studied rapidly oscillating Ap (roAp) stars, with a frequency spectrum of alternating even- and odd-� modes that are distorted by the presence of a strong, global magnetic field. Several recent theoretical studies have found that within the observable

[1]  G. Wade,et al.  High-precision magnetic field measurements of Ap and Bp stars , 2000 .

[2]  D. Kurtz,et al.  New heights in asteroseismology: VLT spectroscopy of the roAp star HD 166473 , 2003 .

[3]  Lionel Bigot,et al.  The oblique pulsator model revisited , 2002 .

[4]  S. Bus,et al.  A frequency analysis of new observations of the rapidly oscillating AP star HD 217522 : evidence for mode-switching. , 1991 .

[5]  S. D. Kawaler,et al.  Discovery of the ‘missing’ mode in HR 1217 by the Whole Earth Telescope , 2002 .

[6]  G. Mathys,et al.  The core-wing anomaly of cool Ap stars. Abnormal Balmer Profiles , 2001 .

[7]  G. Mathys,et al.  Spectropolarimetry of magnetic stars - VI. Longitudinal field, crossover and quadratic field: New measurements , 1997 .

[8]  S. Bagnulo,et al.  Interpretation of the Core-Wing Anomaly of Balmer Line Profiles of Cool Ap Stars , 2002 .

[9]  M. Tassoul,et al.  Second-Order Asymptotic Approximations for Stellar Nonradial Acoustic Modes , 1990 .

[10]  João Fernandes,et al.  Seismic tests of the structure of rapidly oscillating Ap stars: HR 1217 , 2003 .

[11]  Radial Velocity Variations in Pulsating Ap Stars. II. 33 Librae , 2003, astro-ph/0307343.

[12]  G. Preston.  The Unique Magnetic and Spectrum Variations of HD 24712 , 1972 .

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

[14]  I. Baldry,et al.  Time-series spectroscopy of the rapidly oscillating Ap star HR 3831 , 2000, astro-ph/0004390.

[15]  Alfred Gautschy,et al.  Axisymmetric p‐mode pulsations of stars with dipole magnetic fields , 2004 .

[16]  D. Kurtz,et al.  The rich p-mode spectrum of the rapidly oscillating peculiar A star HD 60435 , 1987 .

[17]  P. R. Goode,et al.  Magnetic Effects on Oscillations in roAp Stars , 1996 .

[18]  Douglas Gough,et al.  Magnetic perturbations to the acoustic modes of roAp stars , 2000 .

[19]  Donald W. Kurtz,et al.  The high-overtone p-mode spectrum of the rapidly oscillating Ap star HR 1217 (HD 24712) - Results of a frequency analysis of 324 hr of multi-site photometric observations obtained during a 46-d time-span in 1986 , 1989 .

[20]  D. Kurtz,et al.  The determination of the rotational periods of Rapidly Oscillating Ap stars from their mean light variations – III. HR 3831 (HD 83368) , 1987 .

[21]  T. Ryabchikova,et al.  Time-resolved spectroscopy of the roAp star $\gamma$ Equ , 2001 .

[22]  G. Walker,et al.  Detection of Radial Velocity Variations in the Rapidly Oscillating AP Star HR 1217 , 1987 .

[23]  L. Balona,et al.  Radial velocity study of the roAp star HR 1217 , 2002 .

[24]  I. Baldry,et al.  Spectroscopy of the roAp star α Cir ‐‐ II. The bisector and equivalent width of the Hα line , 1998, astro-ph/9809281.

[25]  Nikolai Piskunov,et al.  Abundance stratification and pulsation in the atmosphere of the roAp star $\boldmath\gamma$ Equulei , 2002 .

[26]  S. Wolff,et al.  A SEARCH FOR AP STARS WITH VERY LONG PERIODS , 1973 .

[27]  Gerald Handler,et al.  Frequency variability in the rapidly oscillating Ap star HR 3831: three more years of monitoring , 1997 .

[28]  Neil J. Balmforth,et al.  Excitation Mechanism in roAp Stars , 2001 .

[29]  O. Kochukhov.  Indirect imaging of nonradial pulsations in a rapidly oscillating Ap star , 2004 .

[30]  M. Tassoul,et al.  Asymptotic approximations for stellar nonradial pulsations , 1980 .

[31]  Jaymie M. Matthews,et al.  Parallaxes versus p-Modes: Comparing Hipparcos and Asteroseismic Results for Pulsating Ap Stars , 1999 .

[32]  T. Ryabchikova,et al.  Pulsational and rotational line profile variations of the roAp stars $\alpha$ Cir and HR 3831 , 2001 .