Discovery of an eclipsing dwarf nova in the ancient nova shell Te 11

Abstract

We report on the discovery of an eclipsing dwarf nova (DN) inside the\npeculiar, bilobed nebula Te 11. Modelling of high-speed photometry of the\neclipse finds the accreting white dwarf to have a mass 1.18 M$_\\odot$ and\ntemperature 13 kK. The donor spectral type of M2.5 results in a distance of 330\npc, colocated with Barnard's loop at the edge of the Orion-Eridanus\nsuperbubble. The perplexing morphology and observed bow shock of the\nslowly-expanding nebula may be explained by strong interactions with the dense\ninterstellar medium in this region. We match the DN to the historic nova of 483\nCE in Orion and postulate that the nebula is the remnant of this eruption. This\nconnection supports the millennia time scale of the post-nova transition from\nhigh to low mass-transfer rates. Te 11 constitutes an important benchmark\nsystem for CV and nova studies as the only eclipsing binary out of just three\nDNe with nova shells.\n