Holger Stiele (NTHU), Albert Kong (NTHU)
The ultra luminous X-ray source XMMU 122939.7+075333 is located in the metal rich globular cluster RZ 2109 in the massive Virgo elliptical galaxy NGC 4472 (M49). Previous studies showed that this ultra luminous source varies between bright and faint phases on timescales of just a few hours. We present the discovery of two peculiar X-ray bursting events that last for about 8 and 3.5 hours separated by about 3 days. Such a recurring X-ray burst-like behaviour has never been observed before. We argue that type-I X-ray bursts or super bursts as well as outburst scenarios requiring a young stellar object are highly unlikely explanations for the observed light curve, leaving an aperiodic disc-wind scenario driven by hyper-Eddington accretion as a viable explanation for this new type of X-ray flaring activities.