EDP Sciences
Free access
Issue
A&A
Volume 403, Number 3, June I 2003
Page(s) 1101 - 1104
Section Formation and evolution of planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20030394


A&A 403, 1101-1104 (2003)
DOI: 10.1051/0004-6361:20030394

White-light oscillations during a flare on II Peg

M. Mathioudakis1, J. H. Seiradakis2, D. R. Williams3, S. Avgoloupis2, D. S. Bloomfield1 and R. T. J. McAteer1

1  Department of Pure and Applied Physics, Queens University Belfast, Belfast BT7 1NN, Northern Ireland, UK
2  University of Thessaloniki, Department of Physics, Section of Astrophysics Astronomy and Mechanics, 54124 Thessaloniki, Greece
3  Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey, RH5 6NT, UK

(Received 14 January 2003 / Accepted 11 March 2003)

Abstract
We analyse the intensity oscillations observed in the gradual phase of a white-light flare on the RS CVn binary II Peg. Fast Fourier Transform power spectra and Wavelet analysis reveal a period of 220 s. The reliability of the oscillation is tested using several criteria. Oscillating coronal loop models are used to derive physical parameters such as temperature, electron density and magnetic field strength associated with the coronal loop. The derived parameters are consistent with the near-simultaneous X-ray observations of the flare. There is no evidence for oscillations in the quiescent state of the binary.


Key words: waves -- stars: flare -- stars: binaries: spectroscopic -- stars: oscillations -- stars: magnetic fields

Offprint request: M. Mathioudakis, M.Mathioudakis@qub.ac.uk

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