Swift observations of the March 2011 outburst of the cataclysmic variable NSV 1436: A probable dwarf nova

Abstract

Aims. The March 2011 outburst of the poorly-studied cataclysmic variable NSV 1436 offered an opportunity to decide between dwarf nova and recurrent nova classifications. Methods. We use seven daily observations in the X-ray and UV by the Swift satellite, together with AAVSO V photometry, to characterise the outburst and decline behaviour. Results. The short optical outburst coincided with a faint and relatively soft X-ray state, whereas in decline to fainter optical magnitudes the X-ray source was harder and brighter. These attributes, and the modest optical outburst amplitude, indicate that this was a dwarf nova outburst and not a recurrent nova. The rapid optical fading suggests an orbital period below 2 h. © 2011 ESO.