Pulsations and orbital modulation of the intermediate polar 1WGA J1958.2+3232
Abstract
We present optical photometry, spectroscopy and photopolarimetry, as well as ASCA X-ray observations, of the recently discovered intermediate polar 1WGA J1958.2+3232. Through the first detection of an optical beat frequency, we confirm the previously tentative suggestion that the spin period of the white dwarf is twice the X-ray and optical pulsation period, which we also confirm in each case. We detect an orbital modulation in each of the U, B, V, R and I bands for the first time, and suggest that the true orbital period is the -1d alias of that previously suggested. We also confirm the presence of circular polarization in this system, detecting a variable polarization which has opposite signs in each of the B and R bands. The double peaked pulse profile and oppositely signed polarization pulses suggest that 1WGA J1958.2+3232 accretes onto both magnetic poles via a disc which is truncated relatively close to the white dwarf.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 2002
- DOI:
- 10.1051/0004-6361:20011820
- arXiv:
- arXiv:astro-ph/0201088
- Bibcode:
- 2002A&A...384..195N
- Keywords:
-
- NOVAE;
- CATACLYSMIC VARIABLES;
- STARS: MAGNETIC FIELDS;
- STARS: INDIVIDUAL;
- 1WGA J1958.2+3232;
- Astrophysics
- E-Print:
- All figures now included as postscript