092395

XMM discovered the phenomenon of X-ray quasi-periodic eruptions (QPEs) in 2019.Four such extragalactic systems that repeat on a timescale of a few hours havebeen identified since. The origin of these repeating signals is currentlyunclear but some ideas include disk/radiation pressure instabilities and extrememass ratio inspirals. We have identified a new QPE system which repeats onceevery 25 days i.e. >25x longer than the longest period QPE source. We arerequesting a 30 ks exposure of this new QPE source between flares i.e. duringthe low flux state. Our aim is to measure the quiescent phase spectrum and theburst amplitude and compare them with the rest of the QPEs. Only XMM has thesoft X-ray coverage large enough effective area and the sensitivity to make these measurements. [truncated! Please see actual data for full text]