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E. Shkolnik, G.A.H. Walker (University of British Columbia), D.A. Bohlender (Herzberg Institute of Astrophysics)
We have detected modulation of the Ca II H&K reversal structure in the spectra (R = 110,000) of four out of five 51 Peg-type stars whose planets have orbital periods between 3 and 4 days. The spectra were acquired during four nights at CFHT in 2001 August. The results are preliminary but we see no similar activity for tau Ceti or the Sun, which have no close, Jupiter-mass companions. Saar and Cuntz (2001) predict that short period planets interacting tidally and magnetically with the chromosphere of the parent star would produce detectable effects in the H&K reversals at ~1% level. The nightly variations are coherent in both H and K but we cannot confirm orbital synchronization at this stage.