V838 Mon: A Search for X-rays from a Possible Stellar Merger

V838 Mon is perhaps the most enigmatic and unusual object observed in stellarastrophysics in recent decades. The star underwent an enormous outburst in 2002,resulting in a spectacular system of light echoes whose evolution has been welldocumented by HST. The cause of the outburst remains the subject of vigorousdebate. One possibility is that of a stellar merger. A prediction of this modelis that the envelope of the merger remnant should be magnetically active. If so,V838 Mon should be a luminous Xray source. We propose a 100 ks XMM/EPICobservation that will constrain the merger model for the V838 Mon outburst andwill help characterize the young cluster in which V838 Mon resides. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]