Pulsation period variations in the RRc Lyrae star KIC 5520878

Abstract

Learned et. al. proposed that a sufficiently advanced extra-terrestrial civilization may tickle Cepheid and RR Lyrae variable stars with a neutrino beam at the right time, thus causing them to trigger early and jogging the otherwise very regular phase of their expansion and contraction. This would turn these stars into beacons to transmit information throughout the galaxy and beyond. The idea is to search for signs of phase modulation (in the regime of short pulse duration) and patterns, which could be indicative of intentional, omnidirectional signaling. We have performed such a search among variable stars using photometric data from the Kepler space telescope. In the RRc Lyrae star KIC 5520878, we have found two such regimes of long and short pulse durations. The sequence of period lengths, expressed as time series data, is strongly auto correlated, with correlation coefficients of prime numbers being significantly higher ($p=99.8$\%). Our analysis of this candidate star shows that the prime number oddity originates from two simultaneous pulsation periods and is likely of natural origin. Simple physical models elucidate the frequency content and asymmetries of the KIC 5520878 light curve. Despite this SETI null result, we encourage testing other archival and future time-series photometry for signs of modulated stars. This can be done as a by-product to the standard analysis, and even partly automated.

arXiv commentAccepted for publication in ApJ. 49 pages, 16 figures

References in corpus (19)

• Fourier Techniques for Very Long Astrophysical Time Series Analysis
• The Orbital Evolution of Gas Giant Planets around Giant Stars
• Transiting exoplanets from the CoRoT space mission II. CoRoT-Exo-2b: A transiting planet around an active G star
• Instrument Performance in Kepler's First Months
• Metal Abundances, Radial Velocities and other Physical Characteristics for the RR Lyrae Stars in the Kepler Field
• The Roche limit for close-orbiting planets: Minimum density, composition constraints, and application to the 4.2-hour planet KOI 1843.03
• Does Kepler unveil the mystery of the Blazhko effect? First detection of period doubling in Kepler Blazhko RR Lyrae stars
• First Kepler results on RR Lyrae stars
• The properties of planets around giant stars
• Period doubling bifurcation and high-order resonances in RR Lyrae hydrodynamical models
• Long time-scale behavior of the Blazhko effect from rectified Kepler data
• 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
• Revisiting CoRoT RR Lyrae stars: detection of period doubling and temporal variation of additional frequencies
• Discovery of period doubling in BL Herculis stars of the OGLE survey. Observations and theoretical models
• The historical vanishing of the Blazhko effect of RR Lyr from GEOS and Kepler surveys
• Predicted and empirical radii of RR Lyrae stars
• Cepheid investigations using the Kepler space telescope
• A Hybrid Mode Model of the Blazhko Effect, Shown to Accurately Fit Kepler Data for RR Lyr

Cited by in corpus (12)

• Strange nonchaotic stars
• The first light curve modeling and orbital period change investigation of nine contact binaries around the short period cut-off
• TESS observations of Cepheid stars: first light results
• An RR Lyrae family portrait: 33 stars observed in Pisces with K2-E2
• The Vanishing & Appearing Sources during a Century of Observations project: I. USNO objects missing in modern sky surveys and follow-up observations of a "missing star"
• Sonneberg plate photometry for Boyajian's Star in two passbands
• Simple nonlinear models suggest variable star universality
• Interstellar communication. IV. Benchmarking information carriers
• One of Everything: The Breakthrough Listen Exotica Catalog
• Square root two period ratios in Cepheid and RR Lyrae variable stars
• The spectral Petersen diagram as a new tool to map pulsation modes in variable stars
• Dynamical properties and search of variable stars: NGC 1960