Asteroseismology of Hybrid Pulsators Made Possible: Simultaneous MOST Space Photometry and Ground-Based Spectroscopy of ? Peg

Autor(en)

Gerald Handler, Jaymie M. Matthews, Rainer Kuschnig, Patrick Lenz, Werner Wolfgang Weiss

Abstrakt

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(en)

Institut für Astrophysik

Externe Organisation(en)

University of British Columbia (UBC)

Journal

The Astrophysical journal Letters

Band

698

Seiten

56-59

Anzahl der Seiten

4

ISSN

2041-8205

Publikationsdatum

2009

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/5e8e09cc-59b9-4abf-b40e-d0b797d59ddb