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Pulsations and orbital modulation of the intermediate polar 1WGA J1958.2+3232

A. J. Norton·H. Quaintrell·S. Katajainen·H. J. Lehto·K. Mukai·I. Negueruela
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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.

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A. J. Norton, H. Quaintrell, S. Katajainen, H. J. Lehto, K. Mukai, I. Negueruela. 2002-01-08. Pulsations and orbital modulation of the intermediate polar 1WGA J1958.2+3232. https://doi.org/10.1051/0004-6361%3A20011820

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