MOST detects variability on τ Bootis A possibly induced by its planetary companion

  title={MOST detects variability on $\tau$ Bootis A possibly induced by its planetary companion},
  author={G. A. H. Walker and Bryce Croll and Jaymie M. Matthews and Rainer Kuschnig and Daniel Huber and Werner W. Weiss and Evgenya L. Shkolnik and Slavek M. Rucinski and David B. Guenther and Anthony F. J. Moffat and Dimitar D. Sasselov},
  journal={Astronomy and Astrophysics},
Context. There is considerable interest in the possible interaction between parent stars and giant planetary companions in 51 Peg-type systems. Aims. We shall demonstrate from MOST satellite photometry and Ca II K line emission that there has been a persistent, variable region on the surface of τ  Boo A, which tracked its giant planetary companion for some 440 planetary revolutions and lies ~68° ($\phi=0.8$) in advance of the sub-planetary point. Methods. The light curves are folded on a range… 

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