The very short supersoft X-ray state of the classical nova M31N 2007-11aM. Henze1, W. Pietsch1, G. Sala2, M. Della Valle3, 4, 5, M. Hernanz6, J. Greiner1, V. Burwitz1, M. J. Freyberg1, F. Haberl1, D. H. Hartmann7, P. Milne8, and G. G. Williams8
1 Max-Planck-Institut für extraterrestrische Physik, 85748 Garching, Germany
2 Departament de Física i Enginyeria Nuclear, EUETIB (UPC/IEEC), Comte d'Urgell 187, 08036 Barcelona, Spain
3 European Southern Observatory (ESO), 85748 Garching, Germany
4 INAF - Napoli, Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, 80131 Napoli, Italy
5 International Centre for Relativistic Astrophysics, Piazzale della Repubblica 2, 65122 Pescara, Italy
6 Institut de Ciències de l'Espai (CSIC-IEEC), Campus UAB, Fac. Ciències, 08193 Bellaterra, Spain
7 Department of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978, USA
8 Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721, USA
Received 23 December 2008 / Accepted 13 March 2009
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 > 1.0 .
Key words: galaxies: individual: M31 -- novae, cataclysmic variables -- stars: individual: nova M31N 2007-11a -- X-rays: galaxies
© ESO 2009