The Detection of a 3.5 hr Period in the Classical Nova Velorum 1999 (V382 Vel) and the Long-Term Behavior of the Nova Light Curve

Aims. We report on recent optical observations of the stellar and the nebular remnants of 22 southern post-novae. Methods. In this study, for each of our targets, we obtained and analysed long-slit spectra in the spectral range 3500-6600 Å and inResults. The changes in the emission lines' equivalent widths with the time since the outburst agree with earlier published results of other authors. We estimated an average value α = 2.37 for the exponent of the power law fitted to the post-novae continua. Our observations clearly show the two-component structure of the V842 Cen expanding nebulae, owing to the different velocities of the ejected matter. We discovered an expanding shell around V382 Vel with an outer diameter of about 12 .

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“…h 5 was detected by Balman et al (2006). Downen et al (2013) estimate the white dwarf mass to be about 1.2 M .…”

Section: V382 Velmentioning

confidence: 98%

“…It was found that V382 Vel is a ONeMg nova (Woodward et al 1999) very similar to V1974 Cygni (Shore et al 2003). An orbital period of 3 h .5 was detected by Balman et al (2006). Downen et al (2013) estimate the white dwarf mass to be about 1.2 M .…”

Section: V382 Velmentioning

confidence: 99%

SALT observations of southern post-novae

Tomov

Swierczynski

Mikołajewski

et al. 2015

A&A

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“…We define this characteristic time as the emergence time of the companion, i.e., t emerge . The orbital period of P orb = 0.1461 days (3.51 hr) was derived by Balman et al (2006) from the orbital modulations with a full amplitude of 0.02 − 0.03 mag while a bit longer orbital period of P orb = 0.1581 days was obtained by Woudt et al (2005). So, we estimate the epoch when the companion emerges from the nova envelope.…”

Section: X-ray Emissionmentioning

confidence: 99%

A Prediction Formula of Supersoft X-Ray Phase of Classical Novae

Hachisu

Kato

2010

ApJ

220

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On the basis of the recently developed universal decline law of classical novae, we propose prediction formulae for supersoft X-ray on and off times, i.e., t X−on = (10 ± 1.8)t 3 days and t X−off = (5.3 ± 1.4)(t 3 ) 1.5 days for 8 t 3 80 days. Here t 3 is the newly proposed "intrinsic" decay time during which the brightness drops by 3 magnitudes from optical maximum along our universal decline law fitted with observation. We have determined the absolute magnitude of our free-free emission model light curves and derived maximum magnitude vs. rate of decline (MMRD) relations. Our theoretical MMRD relations are governed by two parameters, one is the white dwarf (WD) mass and the other is the initial envelope mass at a nova outburst; this second parameter explains the scatter of MMRD points of individual novae. Our theoretical MMRD relations are also in good agreement with the well-known empirical formulae. We also show another empirical relation of M V (15) ∼ −5.7 ± 0.3 based on the absolute magnitude of our model light curves, i.e., the absolute magnitude at 15 days after optical maximum is almost common among various novae. We analyzed ten nova light curves, in which a supersoft X-ray phase was detected, and estimated their WD masses. The models best reproducing simultaneously the optical and supersoft X-ray observations are ONeMg WDs with 1.28 ± 0.04 M ⊙ (V598 Pup), 1.23 ± 0.05 M ⊙ (V382 Vel), 1.15 ± 0.06 M ⊙ (V4743 Sgr), 1.13 ± 0.06 M ⊙ (V1281 Sco), 1.2 ± 0.05 M ⊙ (V597 Pup), 1.06 ± 0.07 M ⊙ (V1494 Aql), 1.04 ± 0.07 M ⊙ (V2467 Cyg), 1.07 ± 0.07 M ⊙ (V5116 Sgr), 1.05 ± 0.05 M ⊙ (V574 Pup), and a CO WD with 0.93 ± 0.08 M ⊙ (V458 Vul). The newly proposed relationships are consistent with the emergence or decay epoch of the supersoft X-ray phase of these ten novae. Finally, we discuss the mechanism of shock-origin hard X-ray component in relation to the emergence of companion star from the WD envelope.

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“…V382 Vel was identified as a very fast neon nova (Woodward et al 1999). The orbital period of 3.5 hr was detected by Balman et al (2006).…”

Section: V446 Her 1960mentioning

confidence: 99%

The Ubv Color Evolution of Classical Novae. Ii. Color–magnitude Diagram

Hachisu

Kato

2016

ApJS

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We have examined the outburst tracks of 40 novae in the color-magnitude diagram (intrinsic B − V color versus absolute V magnitude). After reaching the optical maximum, each nova generally evolves toward blue from the upper-right to the lower-left and then turns back toward the right. The 40 tracks are categorized into one of six templates: very fast nova V1500 Cyg; fast novae V1668 Cyg, V1974 Cyg, and LV Vul; moderately fast nova FH Ser; and very slow nova PU Vul. These templates are located from the left (blue) to the right (red) in this order, depending on the envelope mass and nova speed class. A bluer nova has a less massive envelope and faster nova speed class. In novae with multiple peaks, the track of the first decay is more red than that of the second (or third) decay, because a large part of the envelope mass had already been ejected during the first peak. Thus, our newly obtained tracks in the color-magnitude diagram provide useful information to understand the physics of classical novae. We also found that the absolute magnitude at the beginning of the nebular phase is almost similar among various novae. We are able to determine the absolute magnitude (or distance modulus) by fitting the track of a target nova to the same classification of a nova with a known distance. This method for determining nova distance has been applied to some recurrent novae and their distances have been recalculated.

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The Detection of a 3.5 hr Period in the Classical Nova Velorum 1999 (V382 Vel) and the Long-Term Behavior of the Nova Light Curve

Cited by 11 publications

References 37 publications

SALT observations of southern post-novae

SALT observations of southern post-novae

A Prediction Formula of Supersoft X-Ray Phase of Classical Novae

The Ubv Color Evolution of Classical Novae. Ii. Color–magnitude Diagram

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