Recurrent star-spot activity and differential rotation in KIC 11560447

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Ozavci İ., ŞENAVCI H. V., Isik E., Hussain G. A. J., O'Neal D., YILMAZ M., ...Daha Fazla

Monthly Notices of the Royal Astronomical Society, cilt.474, sa.4, ss.5534-5548, 2018 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 474 Sayı: 4
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1093/mnras/stx3053
  • Dergi Adı: Monthly Notices of the Royal Astronomical Society
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.5534-5548
  • Anahtar Kelimeler: stars: activity, binaries: close, binaries: eclipsing, stars: late-type, stars: rotation, star-spots, LIGHT CURVES, ECLIPSING BINARIES
  • Ankara Üniversitesi Adresli: Evet

Özet

© 2017 The Authors.We present a detailed analysis of surface inhomogeneities on the K1-type subgiant component of the rapidly rotating eclipsing binaryKIC 11560447, using high-precisionKepler light curves spanning nearly 4 yr, which corresponds to about 2800 orbital revolutions. We determine the system parameters precisely, using high-resolution spectra from the 2.1-m Otto Struve Telescope at theMcDonald Observatory. We apply the maximum entropy method to reconstruct the relative longitudinal spot occupancy. Our numerical tests show that the procedure can recover large-scale random distributions of individually unresolved spots, and it can track the phase migration of up to three major spot clusters. By determining the drift rates of various spotted regions in orbital longitude, we suggest a way to constrain surface differential rotation and we show that the results are consistent with periodograms. The K1IV star exhibits two mildly preferred longitudes of emergence, indications of solar-like differential rotation, and a 0.5-1.3-yr recurrence period in star-spot emergence, accompanied by a secular increase in the axisymmetric component of spot occupancy.