Kepler photometry of the prototypical Blazhko star RR Lyr: An old friend seen in a new light

Abstract

We present our analysis of the long cadence Kepler data for the well-studied Blazhko star RR Lyr, gathered during the first two quarters of the satellite's observations and covering a total of 127d. Besides being of great importance for our understanding of RR Lyrae stars in general, these RR Lyr data can be regarded as a case study for observations of bright stars with Kepler. Kepler can perform high-precision photometry on targets like RR Lyr, as the saturated flux is conserved to a very high degree. The Kepler data on RR Lyr are revolutionary in several respects. Even with long-cadence sampling (one measurement per 29.4 min), the unprecedented precision (< mmag) of the Kepler photometry allows the study of the star's extreme light curve variations in detail. The multiplet structures at the main frequency and its harmonics, typical for Blazhko stars, are clearly detected up to the quintuplets. For the first time, photometric data of RR Lyr reveal the presence of half-integer frequencies, linked to a period doubling effect. This phenomenon may be connected to the still unexplained Blazhko modulation. Moreover, with three observed Blazhko cycles at our disposal, we observe that there is no exact repetition in the light curve changes from one modulation cycle to the next for RR Lyr. This may be due to additional periodicities in the star, or to transient or quasi-periodic changes.

arXiv comment14 pages, 12 figures, accepted for publication in MNRAS

References in corpus (13)

• Kepler Mission Design, Realized Photometric Performance, and Early Science
• Overview of the Kepler Science Processing Pipeline
• Kepler Asteroseismology Program: Introduction and First Results
• Initial Characteristics of Kepler Long Cadence Data For Detecting Transiting Planets
• The Kepler Pixel Response Function
• Kepler Science Operations
• First Kepler results on RR Lyrae stars
• The MACHO Project Large Magellanic Cloud variable star inventory. XI. Frequency analysis of the fundamental mode RR Lyrae stars
• Nonlinear Beat Cepheid and RR Lyrae Models
• An extensive photometric study of the Blazhko RR Lyrae star MW Lyr: I. Light curve solution
• An extensive photometric study of the Blazhko RR Lyrae star MW Lyr: II. Changes in the physical parameters
• First quintuplet frequency solution of a Blazhko variable: light curve analysis of RV UMa
• A photometric study of the southern Blazhko star SS For Unambiguous detection of quintuplet components

Cited by in corpus (48)

• The PLATO 2.0 Mission
• Metal Abundances, Radial Velocities and other Physical Characteristics for the RR Lyrae Stars in the Kepler Field
• Exploring the Variable Sky with LINEAR. II. Halo Structure and Substructure Traced by RR Lyrae Stars to 30 kpc
• On the Blazhko Effect in RR Lyrae Stars
• Fourier analysis of non-Blazhko ab-type RR Lyrae stars observed with the Kepler space telescope
• Kepler photometry of RRc stars: peculiar double-mode pulsations and period doubling
• Beyond the Kepler/K2 bright limit: variability in the seven brightest members of the Pleiades
• Period doubling bifurcation and high-order resonances in RR Lyrae hydrodynamical models
• Standard Galactic Field RR Lyrae. I. Optical to Mid-infrared Phased Photometry
• The eccentric massive binary V380 Cyg: revised orbital elements and interpretation of the intrinsic variability of the primary component
• 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
• Why should we correct reported pulsation frequencies for stellar line-of-sight Doppler velocity shifts?
• Blazhko RR Lyrae light curves as modulated signals
• Investigation of systematic effects in Kepler data: Seasonal variations in the light curve of HAT-P-7b
• The CoRoT star 105288363: strong cycle to cycle changes of the Blazhko modulation
• Kepler sheds new and unprecedented light on the variability of a blue supergiant: gravity waves in the O9.5Iab star HD 188209
• TESS observations of Cepheid stars: first light results
• Variability of M giant stars based on Kepler photometry: general characteristics
• The Kepler Cepheid V1154 Cyg revisited: light curve modulation and detection of granulation
• An RR Lyrae family portrait: 33 stars observed in Pisces with K2-E2
• On the distance of the globular cluster M4 (NGC 6121) using RR Lyrae stars: II. Mid-infrared period-luminosity relations
• Bright Blazhko RRab Lyrae stars observed by ASAS and the SuperWASP surveys
• The historical vanishing of the Blazhko effect of RR Lyr from GEOS and Kepler surveys
• Blazhko modulation in the infrared
• The unusually large population of Blazhko variables in the globular cluster NGC 5024 (M53)
• Period doubling and Blazhko modulation in BL Herculis hydrodynamic models
• Data preparation for asteroseismology with TESS
• The all-sky GEOS RR Lyr survey with the TAROT telescopes. Analysis of the Blazhko effect
• Variable turbulent convection as the cause of the Blazhko effect - testing the Stothers model
• Cepheid investigations using the Kepler space telescope
• The K2 Bright Star Survey I: Methodology and Data Release
• Detection of Solar-Like Oscillations, Observational Constraints, and Stellar Models for $\theta$ Cyg, the Brightest Star Observed by the {\it Kepler} Mission
• An In-Depth Spectroscopic Analysis of RR Lyr Variations over the Pulsation Cycle
• An extensive photometric study of the Blazhko RR Lyrae star RZ Lyr
• Period doubling and non-linear resonance in the black hole candidate IGR J17091-3624 ?
• The Blazhko effect and additional excited modes in RR Lyrae stars
• A double-modulation effect detected in a double-mode high-amplitude $\delta$ Scuti star: KIC 10284901
• The Kepler Smear Campaign: Light curves for 102 Very Bright Stars
• Fitting Blazhko light curves
• New results in RR Lyrae modeling: convective cycles, additional modes and more
• Stellar hydrodynamics caught in the act: Asteroseismology with CoRoT and Kepler
• A Study of Pulsation properties of 57 Non-Blazhko effect ab-type RR Lyrae stars with homogeneous metallicities from the LAMOST-Kepler/K2 survey
• An observer's view on the future of asteroseismology
• The space photometry revolution and our understanding of RR Lyrae stars
• Blazhko effect in Cepheids and RR Lyrae stars
• Discovery and Characterization of Three New High-amplitude delta Scuti Stars from TESS Observations
• The Blazhko modulation of TV Boo in 2010