V473 Lyrae, a unique second-overtone Cepheid with two modulation cycles

Abstract

V473 Lyrae is the only Galactic Cepheid with confirmed periodic amplitude and phase variations similar to the Blazhko effect observed in RR Lyrae stars. We collected all available photometric data and some radial velocity measurements to investigate the nature of the modulation. The comparison of the photometric and radial velocity amplitudes confirmed that the star pulsates in the second overtone. The extensive data set, spanning more than 40 years, allowed us to detect a secondary modulation cycle with a period of approximately 5300 days or 14.5 years. The secondary variations can be detected in the period of the primary modulation, as well. Phenomenologically, the light variations are analogous to the Blazhko effect. To find a physical link, we calculated linear hydrodynamic models to search for potential mode resonances that could drive the modulation and found two viable half-integer (n:2) and three n:4 resonances between the second overtone and other modes. If any of these resonances will be confirmed by non-linear models, it may confirm the mode resonance model, a common mechanism that can drive modulations both in RR Lyrae and Cepheid stars.

14 pages, 15 figures, accepted in MNRAS

References in corpus (19)

• Does Kepler unveil the mystery of the Blazhko effect? First detection of period doubling in Kepler Blazhko RR Lyrae stars
• Flavours of variability: 29 RR Lyrae stars observed with Kepler
• On the Blazhko Effect in RR Lyrae Stars
• Nonlinear Beat Cepheid and RR Lyrae Models
• Observational studies of Cepheid amplitudes. I - Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes
• Period doubling bifurcation and high-order resonances in RR Lyrae hydrodynamical models
• Frequency analysis of Cepheids in the Large Magellanic Cloud. New types of classical Cepheid pulsators
• The complex case of V445 Lyr observed with Kepler: Two Blazhko modulations, a non-radial mode, possible triple mode RR Lyrae pulsation, and more
• Blazhko RR Lyrae light curves as modulated signals
• Discovery of period doubling in BL Herculis stars of the OGLE survey. Observations and theoretical models
• The Multi-periodic Blazhko Modulation of CZ Lacertae
• Bright Blazhko RRab Lyrae stars observed by ASAS and the SuperWASP surveys
• Period doubling and Blazhko modulation in BL Herculis hydrodynamic models
• Double-Mode Stellar Pulsations
• Low-dimensional chaos in RR Lyrae models
• Chaos in hydrodynamic BL Herculis models
• The Fly's Eye Camera System -- an instrument design for large étendue time-domain survey
• Analysis of the possible Blazhko-effect Cepheid V473 Lyrae
• New results in RR Lyrae modeling: convective cycles, additional modes and more

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• X-ray Observations of the Peculiar Cepheid V473 Lyr Identify A Low-Mass Companion
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