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X-ray and optical periodicities in X-ray binaries. I.A0535+26

V. Larionov·V. M. Lyuty·G. V. Zaitseva
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Abstract

A homogeneous set of UBV photometry (354 data points obtained between 1983 and 1998) for the Be/X-ray binary A0535+26 = V725Tau is analysed, aiming to look for possible periodic component(s). After subtraction of the long-term variation it was found that only a 103-day periodic component remains in the power spectra in both the V and B colour bands. The probability of chance occurrence of such a peak is less than 0.1%. There are no signs of optical variability at the X-ray period (111 d). We discuss possible reasons for a 103-day modulation and suggest that it corresponds to a beat frequency of the orbital period of the neutron star and the precession period (~1400 d) either of an accretion disc around the neutron star or a warped decretion disc around the Be star.

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V. Larionov, V. M. Lyuty, G. V. Zaitseva. 2001-12-04. X-ray and optical periodicities in X-ray binaries. I.A0535+26. https://doi.org/10.1051/0004-6361%3A20011276

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