We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Durham University

Research & business

View Profile

Publication details for Prof F Richard Stephenson

Shara, Michael M., Drissen, Laurent, Martin, Thomas, Alarie, Alexandre & Stephenson, F. Richard (2017). When does an old nova become a dwarf nova? Kinematics and age of the nova shell of the dwarf nova AT Cancri. Monthly Notices of the Royal Astronomical Society 465(1): 739-745.

Author(s) from Durham


The Z Cam-type dwarf nova AT Cancri (AT Cnc) displays a classical nova (CN) shell, demonstrating that mass transfer in cataclysmic binaries decreases substantially after a CN eruption. The hibernation scenario of cataclysmic binaries predicts such a decrease, on a time-scale of a few centuries. In order to measure the time since AT Cnc's last CN eruption, we have measured the radial velocities of a hundred clumps in its ejecta with SITELLE, Canada–France–Hawaii Telescope's recently commissioned imaging Fourier transform spectrometer. These range from −455 to +490 km s−1. Coupled with the known distance to AT Cnc of 460 pc, the size of AT Cnc's shell, and a simple model of nova ejecta deceleration, we determine that the last CN eruption of this system occurred

yr ago. This is the most rapid transition from a high mass-transfer rate, nova-like variable to a low mass-transfer rate, dwarf nova yet measured, and in accord with the hibernation scenario of cataclysmic binaries. We conclude by noting the similarity in the deduced outburst date (within a century of 1686 CE) of AT Cnc to a ‘guest star’ reported in the constellation Cancer by Korean observers in 1645 CE.