Variability in mode amplitudes in the rapidly oscillating Ap star HR 1217

• Type: Article in International Scientific Journal
• Date: 2011

Authors

White, TR (Author) Other; Bedding, TR (Author) Other; Stello, D (Author) Other; Kurtz, DW (Author) Other; Cunha, MS (Author) FCUP; Gough, DO (Author) Other

Journal

Title: Monthly Notices of the Royal Astronomical Society

Vol. 415

Pages: 1638-1646

ISSN: 0035-8711

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 8 Citations

Other information

Authenticus ID: P-002-P9K

DOI: 10.1111/j.1365-2966.2011.18814.x

Abstract (EN): HR 1217 is one of the best studied rapidly oscillating Ap stars with eight known oscillation modes that are distorted by a strong, global magnetic field. We have reanalysed the multisite observations of HR 1217 taken in 1986 and 2000. We determined a weighting scheme for the 1986 and 2000 data to minimize the noise level. A wavelet analysis of the data has found that the modulation of the amplitude due to rotation for all frequencies is, in general, consistent with the expected modulation for modified l = 1, 2 or 3 modes. Unexpected variations in the rotational modulation are also seen, with variations in the modulation profile, time of maximal pulsation and pulsational energy in each mode. Interestingly, these changes take place on a short time-scale, of the order of days. We consider potential explanations for these behaviours.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9