Cool Stars 14 - Submitted Abstract # 208 This version created on 05 October 2006 Is Stellar X-Ray Activity affected by Close-in Extrasolar Giant Planets? Vinay Kashyap, CfA Jeremy Drake, CfA Steve Saar, CfA We have carried out a survey of X-ray emission from stars with close-in giant planets (CEGP). Of the >150 stars that have been currently identified as possessing planets, a third have been detected in observations carried out with ROSAT and XMM. We carry out detailed statistical analyses, comparing subsamples of stars that have close-in planets with stars that have more distant planets, and find strong evidence that stars with close-in giant planets are on average more X-ray active by a factor $\gtrsim 3$ than those with planets that are more distant. We thus conclude that CEGPs may measurably affect the X-ray activity of the host star. ----------------------------------