The magnetic SW Sextantis star RXJ1643.7+3402
Abstract
We present time-resolved spectroscopy and circular spectropolarimetry of the SW Sex star RXJ1643.7+3402. We find significant polarization levels exhibiting a variability at a period of 19.38 +/- 0.39 min. In addition, emission-line flaring is found predominantly at twice the polarimetric period. These two findings are strong evidences in favour of the presence of a magnetic white dwarf in the system. We interpret the measured periodicities in the context of our magnetic accretion model for SW Sex stars. In contrast with LS Pegasi - the first SW Sex star discovered to have modulated circular polarization - the polarization in RXJ1643.7+3402 is suggested to vary at 2(ω - Ω), while the emission lines flare at (ω - Ω). However, a 2ω/ω interpretation cannot be ruled out. Together with LS Peg and V795 Her, RXJ1643.7+3402 is the third SW Sex star known to exhibit modulated circular polarization.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2009
- DOI:
- 10.1111/j.1365-2966.2009.14585.x
- arXiv:
- arXiv:0902.1799
- Bibcode:
- 2009MNRAS.395..973R
- Keywords:
-
- accretion;
- accretion discs;
- magnetic fields;
- polarization;
- binaries: close;
- stars: individual: RXJ1643.7+3402;
- novae;
- cataclysmic variables;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 7 pages, 4 figures, accepted for publication in MNRAS