Recurrent Novae: What Do We Know about Them?

Anupama, G. C.

doi:10.1017/s1743921312014913

Cited by 10 publications

(6 citation statements)

References 38 publications

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“…Depending on the main source of the energy the symbiotics can be divided into two groups: (a) Symbiotics with steady nuclear burning, in which the mass accretion rate is high enough to maintain (fuel) steady nuclear burning; and (b) Accretion powered symbiotics, in which the mass accretion rate is below the limit of steady nuclear burning and the energy source is the accretion. The accretion-powered symbiotics can display recurrent nova outbursts-the best examples probably are RS Oph and T CrB (Anupama 2013) and collimated jets-for example, CH Cyg, MWC 560, and PN Sa 3-22 (Leedjarv 2004).…”

Section: Discussionmentioning

confidence: 99%

The symbiotic binary ZZ CMi: Intranight variability and suggested outbursting nature

et al. 2021

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We present photometric and spectral observations of the symbiotic star ZZ CMi.We detect intranight variability-flickering and smooth variations in U band.The amplitude of the flickering is about 0.10 − 0.20 mag in U band. In the B band, the variability is lower, with amplitude ≤ 0.03 mag. We also detect variability in the H𝛼 and H𝛽 emission lines, and find an indication for outflow with velocity of about 120-150 km/s. The results indicate that ZZ CMi is an accretion-powered symbiotic containing an M4-M6 III cool component with a white dwarf resembling recurrent novae and jet-ejecting symbiotic stars.

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Section: Discussionmentioning

confidence: 99%

The symbiotic binary ZZ CMi: Intranight variability and suggested outbursting nature

et al. 2021

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“…Classical novae (CNe) outbursts occur in AWB systems on the surface of the WD as a result of an explosive burning of accreted material (Thermonuclear Runaway-TNR) causing the ejection of 10 −7 to 10 −3 M ⊙ of material at velocities up to several thousand kilometers per second (Shara, 1989;Livio, 1994;Starrfield, 2001;Bode and Evans, 2008). The classical nova systems have an initial low level accretion phase (≤10 −10 M ⊙ yr −1 ; see Hillman et al in this Special Issue), where the recurrent nova (RN) that is found in outburst with 20-100 years of occurance time, generally show higher accretion rates at the level of 10 −8 -10 −7 M ⊙ yr −1 (Anupama, 2013). Once the critical pressure at the base of the WD envelope is reached (e.g., 10 19 dyn cm −2 ) the temperatures reach T∼10 8 K under semi-degenerate conditions, and a TNR occurs, resulting in the explosive burning of the hydrogen on the surface of the WD.…”

Section: X-ray Observations Of Classical and Recurrent Novaementioning

confidence: 97%

Accretion flows in nonmagnetic white dwarf binaries as observed in X-rays

Balman

2020

Advances in Space Research

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Cataclysmic Variables (CVs) are compact binaries with white dwarf (WD) primaries. CVs and other accreting WD binaries (AWBs) are useful laboratories for studying accretion flows, gas dynamics, outflows, transient outbursts, and explosive nuclear burning under different astrophysical plasma conditions. They have been studied over decades and are important for population studies of galactic X-ray sources. Recent space-and ground-based high resolution spectral and timing studies, along with recent surveys indicate that we still have observational and theoretical complexities yet to answer. I review accretion in nonmagnetic AWBs in the light of X-ray observations. I present X-ray diagnostics of accretion in dwarf novae and the disk outbursts, the nova-like systems, and the state of the research on the disk winds and outflows in the nonmagnetic CVs together with comparisons and relations to classical and recurrent nova systems, AM CVns and Symbiotic systems. I discuss how the advective hot accretion flows (ADAF-like) in the inner regions of accretion disks (merged with boundary layer zones) in nonmagnetic CVs explain most of the discrepancies and complexities that have been encountered in the X-ray observations. I stress how flickering variability studies from optical to X-rays can be probes to determine accretion history and disk structure together with how the temporal and spectral variability of CVs are related to that of LMXBs and AGNs. Finally, I discuss the nature of accretion in nonmagnetic WDs in terms of ADAF-like accretion flows, and elaborate on the solutions it brings and its complications, constructing an observational framework to motivate new theoretical calculations that introduce this flow-type in disks, outflow and wind models together with disk-instability models of outbursts and nova outbursts in AWBs and WD physics, in general.

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“…The next two columns shows the binary orbital period and mass of the white dwarf and the last two columns give the brightness in V band measured during the outburst peak and quiescence. References: (Schaefer 2010;Anupama 2013).…”

Section: Introductionmentioning

confidence: 99%

Disc instabilities and nova eruptions in symbiotic systems: RS Ophiuchi and Z Andromedae

Bollimpalli

Hameury

Lasota

2018

Monthly Notices of the Royal Astronomical Society

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Using the disc instability model for dwarf novae and soft X-ray transients, we investigate the stability of accretion discs in long-period binary systems. We simulate outbursts due to this thermal-viscous instability for two symbiotic systems, RS Ophiuchi and Z Andromedae. The outburst properties deduced from our simulations suggest that, although the recurrent nova events observed in RS Oph are due to a thermonuclear runaway at the white dwarf surface, these runaways are triggered by accretion disc instabilities. In quiescence, the disc builds up its mass and it is only during the disc-instability outburst that mass is accreted on to the white dwarf at rates comparable to or larger than the mass-transfer rate. For a mass-transfer rate in the range 10 −8 to 10 −7 M yr −1 , the accretion rate and the mass accreted are sufficient to lead to a thermonuclear runaway during one of a series of a few dwarf nova outbursts, barely visible in the optical, but easily detectable in X-rays. In the case of Z And, persistent irradiation of the disc by the very hot white-dwarf surface strongly modifies the dwarf-nova outburst properties, making them significant only for very high mass-transfer rates, of the order of 10 −6 M yr −1 , much higher than the expected secular mean in this system. It is thus likely that the so-called 'combination nova' outburst observed in years 2000 to 2002 was triggered not by a dwarf-nova instability but by a mass-transfer enhancement from the giant companion, leading to an increase in nuclear burning at the accreting white-dwarf surface.

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Recurrent Novae: What Do We Know about Them?

Cited by 10 publications

References 38 publications

The symbiotic binary ZZ CMi: Intranight variability and suggested outbursting nature

The symbiotic binary ZZ CMi: Intranight variability and suggested outbursting nature

Accretion flows in nonmagnetic white dwarf binaries as observed in X-rays

Disc instabilities and nova eruptions in symbiotic systems: RS Ophiuchi and Z Andromedae

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