A theoretical light-curve model for the recurrent nova V394 Coronae Australis

Izumi Hachisu, Mariko Kato

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

A theoretical light curve for the 1987 outburst of V394 Coronae Australis (V394 CrA) is modeled to obtain various physical parameters of this recurrent nova. We then apply the same set of parameters to a quiescent phase and confirm that these parameters give a unified picture of the binary. Our V394 CrA model consists of a very massive white dwarf (WD), with an accretion disk (ACDK) having a flaring-up rim, and a lobe-filling, slightly evolved, main-sequence star (MS). The model includes irradiation effects of the MS and the ACDK by the WD. The early visual light curve (t ∼ 1-10 days after the optical maximum) is well reproduced by a thermonuclear runaway model on a very massive WD close to the Chandrasekhar limit (1.37 ± 0.01 M). The ensuing plateau phase (t ∼ 10-30 days) is also reproduced by the combination of a slightly irradiated MS and a fully irradiated flaring-up disk with a radius ∼ 1.4 times the Roche lobe size. The best-fit parameters are the WD mass ∼1.37 M, the companion mass ∼1.5 M (0.8-2.0 M is acceptable), the inclination angle of the orbit i ∼ 65°-68°, and the flaring-up rim ∼0.30 times the disk radius. The envelope mass at the optical peak is estimated to be ∼6 × 10-6 M, which indicates an average mass accretion rate of ∼1.5 × 10-7 M yr-1 during the quiescent phase between the 1949 and 1987 outbursts. In the quiescent phase, we properly include the accretion luminosity of the WD and the viscous luminosity of the ACDK as well as the irradiation effects of the ACDK and MS by the WD. The observed light curve can be reproduced with a disk size of 0.7 times the Roche lobe size and a rather slim thickness of 0.05 times the accretion disk size at the rim. About 0.5 mag sinusoidal variation of the light curve requires a mass accretion rate higher than ∼1.0 × 10-7 M yr-1, which is consistent with the above estimation from the 1987 outburst. These newly obtained quantities are exactly the same as those predicted in a new progenitor model of Type Ia supernovae.

Original languageEnglish
Pages (from-to)447-451
Number of pages5
JournalAstrophysical Journal
Volume540
Issue number1 PART 1
Publication statusPublished - 2000 Sep 1

Fingerprint

accretion disks
coronas
light curve
main sequence stars
corona
accretion
rims
lobes
outburst
luminosity
irradiation
radii
inclination
supernovae
plateaus
envelopes
orbits
plateau
parameter
flaring

Keywords

  • Accretion, accretion disks
  • Binaries: close
  • Novae, cataclysmic variables
  • Stars: individual (V394 Coronae Australis)

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

A theoretical light-curve model for the recurrent nova V394 Coronae Australis. / Hachisu, Izumi; Kato, Mariko.

In: Astrophysical Journal, Vol. 540, No. 1 PART 1, 01.09.2000, p. 447-451.

Research output: Contribution to journalArticle

Hachisu, I & Kato, M 2000, 'A theoretical light-curve model for the recurrent nova V394 Coronae Australis', Astrophysical Journal, vol. 540, no. 1 PART 1, pp. 447-451.
Hachisu, Izumi ; Kato, Mariko. / A theoretical light-curve model for the recurrent nova V394 Coronae Australis. In: Astrophysical Journal. 2000 ; Vol. 540, No. 1 PART 1. pp. 447-451.
@article{30cd7aad05894ee9a9072539a0ef0f48,
title = "A theoretical light-curve model for the recurrent nova V394 Coronae Australis",
abstract = "A theoretical light curve for the 1987 outburst of V394 Coronae Australis (V394 CrA) is modeled to obtain various physical parameters of this recurrent nova. We then apply the same set of parameters to a quiescent phase and confirm that these parameters give a unified picture of the binary. Our V394 CrA model consists of a very massive white dwarf (WD), with an accretion disk (ACDK) having a flaring-up rim, and a lobe-filling, slightly evolved, main-sequence star (MS). The model includes irradiation effects of the MS and the ACDK by the WD. The early visual light curve (t ∼ 1-10 days after the optical maximum) is well reproduced by a thermonuclear runaway model on a very massive WD close to the Chandrasekhar limit (1.37 ± 0.01 M⊙). The ensuing plateau phase (t ∼ 10-30 days) is also reproduced by the combination of a slightly irradiated MS and a fully irradiated flaring-up disk with a radius ∼ 1.4 times the Roche lobe size. The best-fit parameters are the WD mass ∼1.37 M⊙, the companion mass ∼1.5 M⊙ (0.8-2.0 M⊙ is acceptable), the inclination angle of the orbit i ∼ 65°-68°, and the flaring-up rim ∼0.30 times the disk radius. The envelope mass at the optical peak is estimated to be ∼6 × 10-6 M⊙, which indicates an average mass accretion rate of ∼1.5 × 10-7 M⊙ yr-1 during the quiescent phase between the 1949 and 1987 outbursts. In the quiescent phase, we properly include the accretion luminosity of the WD and the viscous luminosity of the ACDK as well as the irradiation effects of the ACDK and MS by the WD. The observed light curve can be reproduced with a disk size of 0.7 times the Roche lobe size and a rather slim thickness of 0.05 times the accretion disk size at the rim. About 0.5 mag sinusoidal variation of the light curve requires a mass accretion rate higher than ∼1.0 × 10-7 M⊙ yr-1, which is consistent with the above estimation from the 1987 outburst. These newly obtained quantities are exactly the same as those predicted in a new progenitor model of Type Ia supernovae.",
keywords = "Accretion, accretion disks, Binaries: close, Novae, cataclysmic variables, Stars: individual (V394 Coronae Australis)",
author = "Izumi Hachisu and Mariko Kato",
year = "2000",
month = "9",
day = "1",
language = "English",
volume = "540",
pages = "447--451",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1 PART 1",

}

TY - JOUR

T1 - A theoretical light-curve model for the recurrent nova V394 Coronae Australis

AU - Hachisu, Izumi

AU - Kato, Mariko

PY - 2000/9/1

Y1 - 2000/9/1

N2 - A theoretical light curve for the 1987 outburst of V394 Coronae Australis (V394 CrA) is modeled to obtain various physical parameters of this recurrent nova. We then apply the same set of parameters to a quiescent phase and confirm that these parameters give a unified picture of the binary. Our V394 CrA model consists of a very massive white dwarf (WD), with an accretion disk (ACDK) having a flaring-up rim, and a lobe-filling, slightly evolved, main-sequence star (MS). The model includes irradiation effects of the MS and the ACDK by the WD. The early visual light curve (t ∼ 1-10 days after the optical maximum) is well reproduced by a thermonuclear runaway model on a very massive WD close to the Chandrasekhar limit (1.37 ± 0.01 M⊙). The ensuing plateau phase (t ∼ 10-30 days) is also reproduced by the combination of a slightly irradiated MS and a fully irradiated flaring-up disk with a radius ∼ 1.4 times the Roche lobe size. The best-fit parameters are the WD mass ∼1.37 M⊙, the companion mass ∼1.5 M⊙ (0.8-2.0 M⊙ is acceptable), the inclination angle of the orbit i ∼ 65°-68°, and the flaring-up rim ∼0.30 times the disk radius. The envelope mass at the optical peak is estimated to be ∼6 × 10-6 M⊙, which indicates an average mass accretion rate of ∼1.5 × 10-7 M⊙ yr-1 during the quiescent phase between the 1949 and 1987 outbursts. In the quiescent phase, we properly include the accretion luminosity of the WD and the viscous luminosity of the ACDK as well as the irradiation effects of the ACDK and MS by the WD. The observed light curve can be reproduced with a disk size of 0.7 times the Roche lobe size and a rather slim thickness of 0.05 times the accretion disk size at the rim. About 0.5 mag sinusoidal variation of the light curve requires a mass accretion rate higher than ∼1.0 × 10-7 M⊙ yr-1, which is consistent with the above estimation from the 1987 outburst. These newly obtained quantities are exactly the same as those predicted in a new progenitor model of Type Ia supernovae.

AB - A theoretical light curve for the 1987 outburst of V394 Coronae Australis (V394 CrA) is modeled to obtain various physical parameters of this recurrent nova. We then apply the same set of parameters to a quiescent phase and confirm that these parameters give a unified picture of the binary. Our V394 CrA model consists of a very massive white dwarf (WD), with an accretion disk (ACDK) having a flaring-up rim, and a lobe-filling, slightly evolved, main-sequence star (MS). The model includes irradiation effects of the MS and the ACDK by the WD. The early visual light curve (t ∼ 1-10 days after the optical maximum) is well reproduced by a thermonuclear runaway model on a very massive WD close to the Chandrasekhar limit (1.37 ± 0.01 M⊙). The ensuing plateau phase (t ∼ 10-30 days) is also reproduced by the combination of a slightly irradiated MS and a fully irradiated flaring-up disk with a radius ∼ 1.4 times the Roche lobe size. The best-fit parameters are the WD mass ∼1.37 M⊙, the companion mass ∼1.5 M⊙ (0.8-2.0 M⊙ is acceptable), the inclination angle of the orbit i ∼ 65°-68°, and the flaring-up rim ∼0.30 times the disk radius. The envelope mass at the optical peak is estimated to be ∼6 × 10-6 M⊙, which indicates an average mass accretion rate of ∼1.5 × 10-7 M⊙ yr-1 during the quiescent phase between the 1949 and 1987 outbursts. In the quiescent phase, we properly include the accretion luminosity of the WD and the viscous luminosity of the ACDK as well as the irradiation effects of the ACDK and MS by the WD. The observed light curve can be reproduced with a disk size of 0.7 times the Roche lobe size and a rather slim thickness of 0.05 times the accretion disk size at the rim. About 0.5 mag sinusoidal variation of the light curve requires a mass accretion rate higher than ∼1.0 × 10-7 M⊙ yr-1, which is consistent with the above estimation from the 1987 outburst. These newly obtained quantities are exactly the same as those predicted in a new progenitor model of Type Ia supernovae.

KW - Accretion, accretion disks

KW - Binaries: close

KW - Novae, cataclysmic variables

KW - Stars: individual (V394 Coronae Australis)

UR - http://www.scopus.com/inward/record.url?scp=0034260009&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034260009&partnerID=8YFLogxK

M3 - Article

VL - 540

SP - 447

EP - 451

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 PART 1

ER -