ASTEROSEISMOLOGY OF HYBRID PULSATORS MADE POSSIBLE: SIMULTANEOUSMOSTSPACE PHOTOMETRY AND GROUND-BASED SPECTROSCOPY OF γ PEG

G. Handler, J. M. Matthews, J. A. Eaton, J. Daszyńska-Daszkiewicz, R. Kuschnig, H. Lehmann, E. Rodríguez, A. A. Pamyatnykh, T. Zdravkov, P. Lenz, V. Costa, D. Díaz-Fraile (+17 others)
2009 Astrophysical Journal  
We have acquired simultaneous high-precision space photometry and radial velocities of the bright hybrid Beta Cep/SPB pulsator Gamma Peg. Frequency analyses reveal the presence of six g modes of high radial order together with eight low-order Beta Cep oscillations in both data sets. Mode identification shows that all pulsations have spherical degrees l = 0 - 2. An 8.5 solar mass model reproduces the observed pulsation frequencies; all theoretically predicted modes are detected. We suggest,
more » ... d. We suggest, contrary to previous authors, that Gamma Peg is a single star; the claimed orbital variations are due to g-mode pulsation. Gamma Peg is the first hybrid pulsator for which a sufficiently large number of high-order g modes and low order p and mixed modes have been detected and identified to be usable for in-depth seismic modeling.
doi:10.1088/0004-637x/698/1/l56 fatcat:ynkzgwd7rbczbhta7dqt72ygky