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Long-term photometric behaviour of XZ Dra Binarity or magnetic cycle of a Blazhko type RRab star

J. Jurcsik·J. M. Benko·B. Szeidl
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Abstract

The extended photometry available for XZ Dra, a Blazhko type RR Lyrae star, makes it possible to study its long-term behavior. It is shown that its pulsation period exhibit cyclic, but not strictly regular variations with approx. 7200 d period. The Blazhko period (approx. 76 d) seems to follow the observed period changes of the fundamental mode pulsation with dP_B/dP_0=7.7 x 10^4 gradient. Binary model cannot explain this order of period change of the Blazhko modulation, nevertheless it can be brought into agreement with the O-C data of the pulsation. The possibility of occurrence of magnetic cycle is raised.

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J. Jurcsik, J. M. Benko, B. Szeidl. 2002-07-12. Long-term photometric behaviour of XZ Dra Binarity or magnetic cycle of a Blazhko type RRab star. https://doi.org/10.1051/0004-6361%3A20021301

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