When does an old nova become a dwarf nova? Kinematics and age of the nova shell of the dwarf nova AT Cancri

Shara, Michael M.; Drissen, Laurent; Martin, Thomas; Alarie, Alexandre; Stephenson, F. Richard

Abstract

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 330+135−90 330−90+135 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.

Citation

Shara, M. M., Drissen, L., Martin, T., Alarie, A., & Stephenson, F. R. (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. https://doi.org/10.1093/mnras/stw2753

• Journal Article Type: Article
• Acceptance Date: Oct 21, 2016
• Online Publication Date: Oct 27, 2016
• Publication Date: Feb 11, 2017
• Deposit Date: Jul 25, 2017
• Publicly Available Date: Jul 25, 2017
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 465
• Issue: 1
• Pages: 739-745
• DOI: https://doi.org/10.1093/mnras/stw2753
• Public URL: https://durham-repository.worktribe.com/output/1381079