An XMM-Newton observation of the flare star AU MIC Original Research Article

Preliminary results from an XMM-Newton observation of the active flare star AU Mic are presented. During the observation six flares were observed, along with numerous smaller-scale events. Coronal densities have been obtained using the density-sensitive He-like line triplet of O VII, for both the full observation and the final four flares. High background levels were seen for the initial 20 ks of the observation during the time when the first two flares were observed. The average density during the course of the whole observation was found to be at the low-density limit of the O VII triplet i.e 1×109 cm−3. However, in the case of flares four and five, O VII line ratios appear to indicate the density has increased to 2.0×1010 and 1.0–1.6×1010cm−3.