The very short supersoft X-ray state of the classical nova M31N 2007-11a

Context: Short supersoft X-ray source (SSS) states (durations ≤100 days) of classical novae (CNe) indicate massive white dwarfs that are candidate progenitors of supernovae type Ia.
Aims: We carry out a dedicated optical and X-ray monitoring program of CNe in the bulge of M 31.
Methods: We discovered M31N 2007-11a and determined its optical and X-ray light curve. We used the robotic Super-LOTIS telescope to obtain the optical data and XMM-Newton and Chandra observations to discover an X-ray counterpart to that nova.
Results: Nova M31N 2007-11a is a very fast CN, exhibiting a very short SSS state with an appearance time of 6-16 days after outburst and a turn-off time of 45-58 days after outburst.
Conclusions: The optical and X-ray light curves of M31N 2007-11a suggest a binary containing a white dwarf with M_WD > 1.0 M_sun.

Partly based on observations with XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and NASA.

Table 1 is only available in electronic form at http://www.aanda.org