2010/01/03 by K. Kolenberg, R. Szabó, D. W. Kurtz +29 · 5 citations
Physics and Astronomy · #Amplitude #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Globular cluster #Kepler #Light curve #Optics #Physics #RR Lyrae variable #Stars #Stellar, planetary, and galactic studies #Variable star #astro-ph.SR
paper · pdf · doi:10.1088/2041-8205/713/2/l198
6 pages, 4 figures, accepted for publication in ApJ Letters
arxiv created 2010/01/03 · openalex publication_date 2010/03/31 · arxiv updated 2015/05/14 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
We present the first results of our analyses of selected RR Lyrae stars for which data have been obtained by the Kepler Mission . As expected, we find a significant fraction of the RRab stars to show the Blazhko effect, a still unexplained phenomenon that manifests itself as periodic amplitude and phase modulations of the light curve, on timescales of typically tens to hundreds of days. The long time span of the Kepler Mission of 3.5 yr and the unprecedentedly high precision of its data provide a unique opportunity for the study of RR Lyrae stars. Using data of a modulated star observed in the first roll as a showcase, we discuss the data, our analyses, findings, and their implications for our understanding of RR Lyrae stars and the Blazhko effect. With at least 40% of the RR Lyrae stars in our sample showing modulation, we confirm the high incidence rate that was only found in recent high-precision studies. Moreover, we report the occurrence of additional frequencies, beyond the main pulsation mode and its modulation components. Their half-integer ratio to the main frequency is reminiscent of a period doubling effect caused by resonances, observed for the first time in RR Lyrae stars.