Pulsations of the Oe star ? ophiuchi from MOST satellite photometry and ground-based spectroscopy
- Author(s)
- Gordon A. H. Walker, Rainer Kuschnig, Jaymie M. Matthews, Peter Reegen, Thomas Kallinger, E Kambe, Hideyuki Saio, P Harmanec, David B. Guenther, Anthony F J Moffat, Slavek M. Rucinski, Dimitar Sasselov, Werner Wolfgang Weiss, David A. Bohlender, Hrvoje Bozic, O Hashimoto, P Koubsky, Rudolf Mann, Petr Skoda, M Slechta, D Sudar, Marek Wolf, S. L. Yang
- Abstract
Twenty-four days of highly precise Microvariability and Oscillations of Stars (MOST) satellite photometry obtained in mid-2004 of the rapidly rotating O9.5 V star ? Oph have yielded at least a dozen significant oscillation frequencies between 1 and 10 cycles day-1, clearly indicating its relationship to ß Cephei variables. Eight periods were found in He I ?4922 and Hß line profile variations (LPV) of which six coincide with those from the MOST photometry. This unique photometric and spectroscopic detection of radial and nonradial pulsations leads to a plausible model in which high l-modes are excited when their frequencies in the corotating frame are similar to those of low-order radial modes. We propose that the dominant photometric 4.6 hr period (f1) corresponds to a radial first overtone excited by the ?-mechanism associated with the Fe opacity bump. No unambiguous rotational period can be identified in either the light curve or the LPV. Œ 2005. The American Astronomical Society. All rights reserved.
- Organisation(s)
- Department of Astrophysics, University Sport Institute
- External organisation(s)
- University of British Columbia (UBC), National Defense Academy of Japan, Tohoku University, Czech Academy of Sciences, Saint Mary's University, University of Montreal, University of Toronto, Harvard-Smithsonian Center for Astrophysics, National Research Council Canada (NRC-CNRC), University of Zagreb, Gunma Astronomical Observatory, Charles University Prague, University of Victoria
- Journal
- The Astrophysical Journal: an international review of astronomy and astronomical physics
- Volume
- 623
- Pages
- 145-148
- No. of pages
- 4
- ISSN
- 0004-637X
- Publication date
- 2005
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/b02eb40f-0321-4050-9619-221b76be75fa