Resolving short supersoft source states of optical novae in the core of M31

We propose to continue the monitoring of the M31 core with 5x23ks XMM EPIC and5x20ks Chandra HRCI observations equally distributed from Nov 2010 to mid Feb2011 to determine additional light curves for short supersoft source (SSS)states of optical novae. SSS states with <100 d duration indicate accretingmassive white dwarfs (WDs). They are proposed as SN Ia progenitors and determining their frequency is very important. We will correlate detected sourceswith novae from optical monitoring. With a nova rate in the field of virgul38/yr andSSS states lasting from weeks to years we will follow light curves of manynovae. Durations of the SSS state will allow us to constrain envelop and WDmasses. We will also monitor time variability of virgul200 M31 Xray sources (XRBs) truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]