TY - JOUR
T1 - Optical and supersoft x-ray light-curve models of classical nova v2491 cygni
T2 - A new clue to the secondary maximum
AU - Hachisu, Izumi
AU - Kato, Mariko
N1 - Funding Information:
We thank D. Takei for providing us with their machine-readable X-ray data of V2491 Cyg and also AAVSO and VSOLJ for the optical and near-infrared data for V2491 Cyg, V1493 Aql, and V2362 Cyg. We are grateful to the anonymous referee for useful comments and to D. Takei, M. Tsujimoto, and S. Kitamoto for stimulating discussion on V2491 Cyg. This research has been supported in part by the Grant-in-Aid for Scientific Research (20540227) of the Japan Society for the Promotion of Science.
PY - 2009
Y1 - 2009
N2 - V2491 Cygni (Nova Cygni 2008 No. 2) was detected as a transient supersoft X-ray source with the Swift XRT as early as 40 days after the outburst, suggesting a very massive white dwarf (WD) close to the Chandrasekhar limit. We present a unified model of near infrared, optical, and X-ray light curves for V2491 Cyg, and have estimated, from our best-fit model, the WD mass to be 1.3 0.02 M with an assumed chemical composition of the envelope, X = 0.20, Y = 0.48, X CNO = 0.20, X Ne = 0.10, and Z = 0.02 by mass weight. We strongly recommend detailed composition analysis of the ejecta because some enrichment of the WD matter suggests that the WD mass does not increase like in RS Oph, which is a candidate of Type Ia supernova progenitors. V2491 Cyg shows a peculiar secondary maximum in the optical light curve as well as V1493 Aql and V2362 Cyg. Introducing magnetic activity as an adding energy source to nuclear burning, we propose a physical mechanism of the secondary maxima.
AB - V2491 Cygni (Nova Cygni 2008 No. 2) was detected as a transient supersoft X-ray source with the Swift XRT as early as 40 days after the outburst, suggesting a very massive white dwarf (WD) close to the Chandrasekhar limit. We present a unified model of near infrared, optical, and X-ray light curves for V2491 Cyg, and have estimated, from our best-fit model, the WD mass to be 1.3 0.02 M with an assumed chemical composition of the envelope, X = 0.20, Y = 0.48, X CNO = 0.20, X Ne = 0.10, and Z = 0.02 by mass weight. We strongly recommend detailed composition analysis of the ejecta because some enrichment of the WD matter suggests that the WD mass does not increase like in RS Oph, which is a candidate of Type Ia supernova progenitors. V2491 Cyg shows a peculiar secondary maximum in the optical light curve as well as V1493 Aql and V2362 Cyg. Introducing magnetic activity as an adding energy source to nuclear burning, we propose a physical mechanism of the secondary maxima.
KW - Novae, cataclysmic variables
KW - Stars: individual (V1493 Aql, V2362 Cyg, V2491 Cyg)
KW - Stars: mass loss
KW - X-rays: binaries
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U2 - 10.1088/0004-637X/694/2/L103
DO - 10.1088/0004-637X/694/2/L103
M3 - Article
AN - SCOPUS:64849092076
SN - 0004-637X
VL - 694
SP - L103-L106
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
ER -