A Gaussian Process Regression Reveals No Evidence for Planets Orbiting Kapteyn’s Star

  title={A Gaussian Process Regression Reveals No Evidence for Planets Orbiting Kapteyn’s Star},
  author={Anna Bortle and H. Fausey and Jinbiao Ji and Sarah E. Dodson-Robinson and Victor Ramirez Delgado and John E. Gizis},
  journal={The Astronomical Journal},
Radial–velocity (RV) planet searches are often polluted by signals caused by gas motion at the star’s surface. Stellar activity can mimic or mask changes in the RVs caused by orbiting planets, resulting in false positives or missed detections. Here we use Gaussian process regression to disentangle the contradictory reports of planets versus rotation artifacts from Kapteyn’s star. To model rotation, we use joint quasiperiodic kernels for the RV and Hα signals, requiring that their periods and… 
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