Observations of X-ray oscillations in XI Boo: Evidence of a fast kink mode in the stellar loops

TL;DR

This paper reports the first detection of X-ray oscillations in the star XI Boo, interpreted as a fast kink mode of magnetoacoustic waves, using wavelet and periodogram analyses of XMM-Newton data.

Contribution

First observation of X-ray oscillations in XI Boo, identifying them as a fundamental fast-kink mode in stellar loops.

Findings

Detected 1019 s X-ray oscillations in XI Boo

Oscillations interpreted as fast-kink magnetoacoustic mode

Used wavelet and periodogram analyses for detection

Abstract

We report the observations of X-ray oscillations during the flare in a cool active star XI Boo for the first time. XI 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.