The diffusion-induced nova scenario. CK Vul and PB 8 as possible observational counterparts

Abstract

We propose a scenario for the formation of DA white dwarfs with very thin helium buffers. For these stars we explore the possible occurrence of diffusion-induced CNO- flashes, during their early cooling stage. In order to obtain very thin helium buffers, we simulate the formation of low mass remnants through an AGB final/late thermal pulse (AFTP/LTP scenario). Then we calculate the consequent white dwarf cooling evolution by means of a consistent treatment of element diffusion and nuclear burning. Based on physically sounding white dwarf models, we find that the range of helium buffer masses for these diffusion-induced novas to occur is significantly smaller than that predicted by the only previous study of this scenario. As a matter of fact, we find that these flashes do occur only in some low-mass (M < 0.6M) and low metallicity (Z_ZAMS <0.001) remnants about 10^6 - 10^7 yr after departing from the AGB. For these objects, we expect the luminosity to increase by about 4 orders of magnitude in less than a decade. We also show that diffusion-induced novas should display a very typical eruption lightcurve, with an increase of about a few magnitudes per year before reaching a maximum of M_V ~ -5 to -6. Our simulations show that surface abundances after the outburst are characterized by logNH/NHe ~ -0.15...0.6 and N>C>O by mass fractions. Contrary to previous speculations we show that these events are not recurrent and do not change substantially the final H-content of the cool (DA) white dwarf. (Abridged)

16 pages, 8 figures, 3 tables. Replaced to match the final version published by MNRAS. The definitive version is available at http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2966

References in corpus (24)

• Evolutionary and pulsational properties of white dwarf stars
• The Element Abundances in Bare Planetary Nebula Central Stars and the Shell Burning in AGB Stars
• The Initial-Final Mass Relation: Direct Constraints at the Low Mass End
• A New Version of Reimers' law of Mass Loss Based on a Physical Approach
• New cooling sequences for old white dwarfs
• The formation and evolution of hydrogen-deficient post-AGB white dwarfs: the emerging chemical profile and the expectations for the PG1159-DB-DQ evolutionary connection
• A white dwarf cooling age of 8 Gyr for NGC 6791 from physical separation processes
• Parameterising the third dredge-up in asymptotic giant branch stars
• Semi-empirical white dwarf initial-final mass relationships: a thorough analysis of systematic uncertainties due to stellar evolution models
• Modeling He-rich subdwarfs through the hot-flasher Scenario
• Full evolutionary models for PG1159 stars. Implications for the helium-rich O(He) stars
• New evolutionary models for massive ZZ Ceti stars: I. First results for their pulsational properties
• New evolutionary calculations for the Born Again scenario
• Infrared Photometry and Evolution of Mass-Losing AGB Stars I. Carbon Stars Revisited
• Evolution of white dwarf stars with high-metallicity progenitors: the role of 22Ne diffusion
• What are the Hot R Coronae Borealis Stars?
• Fe emission and ionized excess absorption in the luminous quasar 3C109 with XMM-Newton
• The rise and fall of V4334 Sgr (Sakurai's Object)
• Faint recombination lines in Galactic PNe with [WC] nucleus
• CK Vul as a Candidate Eruptive Stellar Merging Event
• The born again (VLTP) scenario revisited: The mass of the remnants and implications for V4334 Sgr
• On the stability of thermonuclear shell sources in stars
• The central star of the planetary nebula PB 8: a Wolf-Rayet-type wind of an unusual WN/WC chemical composition
• The enigma of the oldest `nova': the central star and nebula of CK Vul

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• New evolutionary sequences for extremely low mass white dwarfs: Homogeneous mass and age determinations, and asteroseismic prospects
• Pulsating white dwarfs: new insights
• A radial velocity survey for post-common-envelope Wolf-Rayet central stars of planetary nebulae: First results and discovery of the close binary nucleus of NGC 5189
• Abell 48 - a rare WN-type central star of a planetary nebula
• Organic molecules, ions, and rare isotopologues in the remnant of the stellar-merger candidate, CK Vulpeculae (Nova 1670)
• The planetary nebula Abell 48 and its [WN] nucleus
• Molecular remnant of Nova 1670 (CK Vulpeculae). II. A three-dimensional view on the gas distribution and velocity field
• IC 4663: The first unambiguous [WN] Wolf-Rayet central star of a planetary nebula
• CKVul: evolving nebula and three curious background stars
• Quiescent nuclear burning in low-metallicity white dwarfs
• CK Vul: a smorgasbord of hydrocarbons rules out a 1670 nova (and much else besides)
• Counterparts of Far Eastern Guest Stars: Novae, supernovae, or something else?
• Bi-abundance ionization structure of the Wolf-Rayet planetary nebula PB 8
• The impact of Coulomb diffusion of ions on the pulsational properties of DA white dwarfs
• Central stars of planetary nebulae: The white dwarf connection
• Are planetary nebulae derived from multiple evolutionary scenarios?
• 3D spatio-kinematic modeling of Abell 48, a planetary nebula around a Wolf-Rayet [WN] star
• The circumstellar dust of "Born-Again" stars
• Was there a (super)nova in 1408?
• Two hot pre-white dwarfs inside the red-giant-branch planetary nebula Pa 13 -- Double core evolution or common envelope-induced rejuvenation?