FIRST KEPLER RESULTS ON RR LYRAE STARS

Journal Article · Tue Apr 20 00:00:00 EDT 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/713/2/L198; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21305030

Kolenberg, K; Guggenberger, E ^[1]; Szabo, R; Benko, J M; Derekas, A; Kollath, Z; Nuspl, J ^[2]; Kurtz, D W ^[3]; Gilliland, R L ^[4]; Christensen-Dalsgaard, J; Kjeldsen, H ^[5]; Brown, T M ^[6]; Chadid, M ^[7]; Criscienzo, M Di ^[8]; Kinemuchi, K ^[9]; Kunder, A ^[10]; Kopacki, G ^[11]; Moskalik, P ^[12]; Nemec, J M ^[13]; Silvotti, R ^[14]

---

1. Institut fuer Astronomie, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria)
2. Konkoly Observatory, H-1525 Budapest, P.O. Box 67 (Hungary)
3. Jeremiah Horrocks Institute of Astrophysics, University of Central Lancashire, Preston PR1 2HE (United Kingdom)
4. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
5. Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)
6. Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States)
7. Observatoire de la Cote d'Azur, Universite Nice Sophia-Antipolis, UMR 6525, Parc Valrose, 06108 Nice Cedex 02 (France)
8. INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monte Porzio Catone, Rome (Italy)
9. Department of Astronomy, 211 Bryant Space Science Center, University of Florida, Gainesville, FL 32611 (United States)
10. Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, La Serena (Chile)
11. Instytut Astronomiczny Uniwersytetu Wroclawskiego, Kopernika 11, 51-622 Wroclaw (Poland)
12. Copernicus Astronomical Centre, ul. Bartycka 18, 00-716 Warsaw (Poland)
13. Department of Physics and Astronomy, Camosun College, Victoria, British Columbia (Canada)
14. INAF-Osservatorio Astronomico di Torino, Strada dell'Osservatorio 20, 10025 Pino Torinese (Italy)

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.

• OSTI ID: 21305030
• Journal Information: Astrophysical Journal Letters, Vol. 713, Issue 2; Other Information: DOI: 10.1088/2041-8205/713/2/L198; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
AMPLITUDES
OSCILLATIONS
PERIODICITY
PULSATIONS
STARS