088105

Suspicious dips have recently been found in the light curves of some young M dwarfs. At first these dips were thought to be transiting exoplanets but the changing phase and depth over time scales of weeks makes an exoplanetary origin unlikely. We suggest the presence of extremely dense slingshot prominences as the cause for this variability. We have recently discovered an M dwarf with this behavior that is very X-ray bright allowing to test the slingshot prominence scenario by testing whether a deep dip in X-rays occurs at the same time as the shallow optical dip. We propose to observe the star for 1.2 rotation periods i.e. a total of 115ks with XMM-EPIC. [truncated! Please see actual data for full text]