Asteroseismology of Hybrid Pulsators Made Possible: Simultaneous MOST Space Photometry and Ground-Based Spectroscopy of ? Peg
- Author(s)
- Gerald Handler, Jaymie M. Matthews, Rainer Kuschnig, Patrick Lenz, Werner Wolfgang Weiss
- Abstract
We have acquired simultaneous high-precision space photometry and radial velocities of the bright hybrid ? Cep/Slowly Pulsating B pulsator ? Peg. Frequency analyses reveal the presence of six gravity (g) modes of high radial order together with eight low-order ? Cep oscillations in both data sets. Mode identification shows that all pulsations have spherical degrees ell = 0-2. An 8.5 M sun model reproduces the observed pulsation frequencies; all theoretically predicted modes in the ? Cep domain are detected. We suggest, contrary to previous authors, that ? Peg is a single star; the claimed orbital variations are due to g-mode pulsation. ? Peg is the first hybrid pulsator for which a sufficiently large number of high-order g modes and low-order pressure (p) and mixed modes have been detected and identified to be usable for in-depth seismic modeling.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- University of British Columbia (UBC)
- Journal
- The Astrophysical journal Letters
- Volume
- 698
- Pages
- 56-59
- No. of pages
- 4
- ISSN
- 2041-8205
- Publication date
- 2009
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1030 Physics, Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/5e8e09cc-59b9-4abf-b40e-d0b797d59ddb