The aftermath of nova Centauri 2013 (V1369 Centauri)

¹ INAF-OATS, Via G.B. Tiepolo 11, 34143 Trieste, Italy
e-mail: elena.mason@inaf.it
² Dipartimento di Fisica “Enrico Fermi”, Università di Pisa & INFN-Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
³ Smithsonian Astrophysical Observatory, MS-03, 60 Garden Street, Cambridge, MA 02138, USA
⁴ Space Science and Astrobiology Division, NASA Ames Research Center, M/S 245-6, Moffett Field, CA 94035, USA
⁵ Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
⁶ Institut für Astronomie & Astrophysik, Eberhard Karls Universität Tübingen, Geschwister-Scholl-Platz, 72074 Tübingen, Germany

Received: 2 December 2020
Accepted: 23 February 2021

Abstract

Context. Classical nova progenitors are cataclysmic variables and very old novae are observed to match systems with high mass transfer rates and (relatively) long orbital periods. However, the aftermath of a classical nova has never been studied in detail.

Aims. We intend to probe the aftermath of a classical nova explosion in cataclysmic variables and observe as the binary system relaxes to quiescence.

Methods. We used multiwavelength time-resolved optical and near-infrared spectroscopy for a bright, well-studied classical nova five years after outburst. We were able to disentangle the contribution of the ejecta at this late epoch using its previous characterization, separating the ejecta emission from that of the binary system.

Results. We determined the binary orbital period (P = 3.76 h), the system separation, and the mass ratio (q ≳ 0.17 for an assumed white dwarf mass of 1.2 M_⊙). We find evidence of an irradiated secondary star and no unambiguous signature of an accretion disk, although we identify a second emission line source tied to the white dwarf with an impact point. The data are consistent with a bloated white dwarf envelope and the presence of unsettled gas within the white dwarf Roche lobe.

Conclusions. At more than 5 years after eruption, it appears that this classical nova has not yet relaxed.