Physics of nova outbursts: A theoretical model of classical nova outbursts with self-consistent wind mass loss. (18th July 2022)

• Record Type: Journal Article
• Authors: Kato, Mariko; Saio, Hideyuki; Hachisu, Izumi
• Is Part Of: Publications of the Astronomical Society of Japan. Volume 74:Number 5(2022)
• Page Start: 1005
• Page End: 1021
• Publication Date: 2022-07-18
• Subjects: novae, cataclysmic variables -- stars: interiors -- stars: mass loss -- white dwarfs -- X-rays: binaries; Astronomy -- Periodicals; 520.5
• DOI: 10.1093/pasj/psac051
• Languages: English
• ISSNs: 0004-6264

Abstract

Abstract: We present a model for one cycle of a classical nova outburst based on a self-consistent wind mass loss accelerated by the gradient of radiation pressure, i.e., so-called optically thick winds. Evolution models are calculated by a Henyey code for a 1.0 $M_{\odot }$ white dwarf with a mass-accretion rate of 5 × 10 −9 $M_{\odot }$ yr −1 . The outermost part of the hydrogen-rich envelope is connected to a steadily moving envelope where optically thick winds occur. We confirm that no internal shock waves occur at thermonuclear runaway. The wind mass-loss rate reaches a peak of 1.4 × 10 −4 $M_{\odot }$ yr −1 at the epoch of the maximum photospheric expansion, where the photospheric temperature decreases to log T ph (K) = 3.90. Almost all of the accreted mass is lost in the wind. The nuclear energy generated in hydrogen burning is lost in a form of photon emission (64%), gravitational energy (lifting up the wind matter against gravity, 35%), and the kinetic energy of the wind (0.23%). A classical nova should be very bright in a far-UV (100–300 Å) band for one day just after the onset of thermonuclear runaway (∼ 25 d before the optical maximum). In the decay phase of the nova outburst, the envelope structure is very close to that of a steady-state solution.