Observations of X-Ray Oscillations in ξ Boo: Evidence of a Fast-Kink Mode in the Stellar Loops

Abstract

We report the observations of X-ray oscillations during the flare in a cool active star ξ Boo for the first time. ξ Boo was observed by EPIC/MOS of the XMM-Newton satellite. The X-ray light curve is investigated with wavelet and periodogram analyses. Both analyses clearly show oscillations of the period of ~1019 s. We interpret these oscillations as a fundamental fast-kink mode of magnetoacoustic waves.