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

TL;DR

This paper reports the discovery of an eclipsing dwarf nova within the nebula Te 11, linking it to a historic nova event and providing insights into post-nova evolution and interactions with the interstellar medium.

Contribution

It is the first eclipsing dwarf nova identified within a nova shell, offering a unique benchmark for studying cataclysmic variables and nova remnants.

Findings

White dwarf mass estimated at 1.18 M_sun

Distance of 330 pc colocates the system with Barnard's loop

Nebula morphology suggests interaction with dense interstellar medium

Abstract

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