The discovery of rapid oscillations in the magnetic Ap stars HD 69013 and HD 96237
Abstract
We report the detection of short-period variations in the stars HD 69013 and HD 96237. These stars possess large overabundances of rare earth elements and global magnetic fields, thus belong to the class of chemically peculiar Ap stars of the main sequence. Pulsations were found from analysis of high time resolution spectra obtained with the European Southern Observatory (ESO) Very Large Telescope using a cross-correlation method for wide spectral bands, from lines belonging to rare earth elements and from the Hα core. Pulsation amplitudes reach more than 200 m s-1 for some lines in HD 69013 with a period of 11.4 min and about 100 m s-1 in HD 96237 with periods near 13.6 min. The pulsations have also been detected in photometric observations obtained at the South African Astronomical Observatory. Based on observations collected at the ESO, Chile, as part of programmes 080.D-0191(A), 078.D-0192(A) and 078.D-0080(A).
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2011
- DOI:
- 10.1111/j.1365-2966.2010.17747.x
- arXiv:
- arXiv:1009.4022
- Bibcode:
- 2011MNRAS.411..978E
- Keywords:
-
- stars: chemically peculiar;
- stars: magnetic field;
- stars: oscillations;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- submitted to MNRAS