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- ID:
- ivo://CDS.VizieR/J/ApJ/788/164
- Title:
- Properties of the known Galactic classical novae
- Short Name:
- J/ApJ/788/164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recurrent novae (RNe) are cataclysmic variables with two or more nova eruptions within a century. Classical novae (CNe) are similar systems with only one such eruption. Many of the so-called CNe are actually RNe for which only one eruption has been discovered. Since RNe are candidate Type Ia supernova progenitors, it is important to know whether there are enough in our Galaxy to provide the supernova rate, and therefore to know how many RNe are masquerading as CNe. To quantify this, we collected all available information on the light curves and spectra of a Galactic, time-limited sample of 237 CNe and the 10 known RNe, as well as exhaustive discovery efficiency records. We recognize RNe as having (1) outburst amplitude smaller than 14.5-4.5xlog(t_3_), (2) orbital period >0.6 days, (3) infrared colors of J-H>0.7 mag and H-K>0.1 mag, (4) FWHM of H{alpha}>2000 km/s, (5) high excitation lines, such as Fe X or He II near peak, (6) eruption light curves with a plateau, and (7) white dwarf mass greater than 1.2 M_{sun}_. Using these criteria, we identify V1721 Aql, DE Cir, CP Cru, KT Eri, V838 Her, V2672 Oph, V4160 Sgr, V4643 Sgr, V4739 Sgr, and V477 Sct as strong RN candidates. We evaluate the RN fraction among the known CNe using three methods to get 24%+/-4%, 12%+/-3%, and 35%+/-3%. With roughly a quarter of the 394 known Galactic novae actually being RNe, there should be approximately a hundred such systems masquerading as CNe.
- ID:
- ivo://CDS.VizieR/J/AJ/152/226
- Title:
- Radial velocities of 35 cataclysmic variables
- Short Name:
- J/AJ/152/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report follow-up studies of 35 recently discovered cataclysmic variables (CVs), 32 of which were found in large, automated synoptic sky surveys. The objects were selected for observational tractability. For 34 of the objects, we present mean spectra and spectroscopic orbital periods, and for one more we give an eclipse-based period. Thirty-two of the period determinations are new, and three of these refine published estimates based on superhump periods. The remaining three of our determinations confirm previously published periods. Twenty of the stars are confirmed or suspected dwarf novae with periods shorter than 3 hr, but we also find three apparent polars (AM Her stars) and six systems with P>5hr. Five of these systems have secondary stars visible in their spectra, from which we estimate distances when possible. The orbital period distribution of this sample is very similar to that of previously discovered CVs.
- ID:
- ivo://CDS.VizieR/J/A+A/603/A72
- Title:
- R light curves of MN Dra
- Short Name:
- J/A+A/603/A72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of an extensive world-wide observing campaign of MN Draconis. MN Draconis is a poorly known active dwarf nova in the period gap and is one of the only two known cases of period gap SU UMa objects showing the negative superhumps. Photometric behaviour of MN Draconis poses a challenge for existing models of the superhump and superoutburst mechanisms. Therefore, thorough investigation of peculiar systems, such as MN Draconis, is crucial for our understanding of evolution of the close binary stars. To measure fundamental parameters of the system, we collected photometric data in October 2009, June-September 2013 and June-December 2015. Analysis of the light curves, O-C diagrams and power spectra was carried out. During our three observational seasons we detected four superoutburts and several normal outbursts. Based on the two consecutive superoutbursts detected in 2015, the supercycle length was derived P_sc_=74+/-0.5-days and it has been increasing with a rate of P_dot_=3.3x10^-3^ during last twelve years. Based on the positive and negative superhumps we calculated the period excess {epsilon}=5.6%+/-0.1%, the period deficit {epsilon}_=2.5%+/-0.6%, and in result, the orbital period P_orb_=0.0994(1)days (143.126+/-0.144min). We updated the basic light curve parameters of MN Draconis. MN Draconis is the first discovered SU UMa system in the period gap with increasing supercycle length.
- ID:
- ivo://CDS.VizieR/J/A+A/452/503
- Title:
- RR Tel JHKL photometry 1975-2002
- Short Name:
- J/A+A/452/503
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A set of photometric observations of the symbiotic nova RR Tel in different wavelength bands - visual from 1949 to 2002 and near-infrared (JHKL) from 1975 to 2002 - are presented. Near-infrared photometry is used to identify and study three periods during which the Mira component was heavily obscured by dust. The variability due to the normal Mira pulsation was removed from the JHKL data, which were then compared with the AAVSO visual light curve. We discuss these obscuration events as observed in the different wavelength bands. A change in the colour trend was observed with the colour becoming redder after JD2446000. Generally J-K was comparable while K-L was larger than typical values for solitary Miras. A distance estimate of 2.5kpc, based on the IR data, is given. A study of the behaviour of the permitted Fe II and forbidden [FeII] emission lines during the 1996-2000 obscuration episode suggests a larger flux decrease for the permitted than for the forbidden lines. No other correlation with line properties have been found. The most attractive model involves obscuration by optically thick clouds in the outer layers.
- ID:
- ivo://CDS.VizieR/J/A+AS/124/425
- Title:
- RR Tel UV emission
- Short Name:
- J/A+AS/124/425
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/639/L12
- Title:
- Search for NLTE modeling for classical nova ejecta
- Short Name:
- J/A+A/639/L12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extreme super-solar abundances of lithium and beryllium have been reported in recent years for classical novae based on absorption lines in ultraviolet and optical spectra during the optically thick stages, but these findings have not been compared with spectrum syntheses of the ejecta. We present a grid of nova ejecta models calculated with PHOENIX aimed at simulating the reported LiI and BeII features with super-solar abundances. We computed a sequence of models, finely exploring the parameter space of effective temperature, ejecta expansion velocity, and Li and Be overabundances. Regardless of temperature and expansion velocity, the synthetic spectra for large Li and Be overabundances strongly disagree with those presented in recent literature. Assuming a wide range of Be overabundances (factors of 100 to 10 000 relative to solar), we predict a much stronger spectroscopic feature at BeII 3130{AA} than those so far observed. A similar overabundance for Li would instead result in a barely observable change in the emitted flux at LiI 6709{AA}. The observed extended absorption feature at 3131{AA} reported in V838 Her and other novae appears even in zero-Be models with only solar abundances (which for novae are underestimates). The computed spectra do not support the lithium and beryllium abundances, and caution is warranted in the interpretation of the phenomenology.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/4341
- Title:
- Seven recent novae BVI light curves
- Short Name:
- J/MNRAS/469/4341
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The BVI light curves of seven recent novae (i.e. V1534 Sco, V1535 Sco, V2949 Oph, V3661 Oph, MASTER OT J010603.18-744715.8, TCP J18102829-2729590 and ASASSN-16ma) have been extensively mapped with daily robotic observations from Atacama (Chile): five belong to the Galactic bulge, one to the Small Magellanic Cloud and another is a Galactic disc object. The two programme novae detected in {gamma}-rays by Fermi-LAT (i.e. TCP J18102829-2729590 and ASASSN-16ma) are bulge objects with unevolved companions. They distinguish themselves by showing a double-component optical light curve. The first component to develop is the fireball from freely expanding, ballistic-launched ejecta, with a time of passage through maximum that is strongly dependent on wavelength (~1d delay between the B and I bands). The second component, emerging simultaneously with the nova detection in {gamma}-rays, evolves at a slower pace, its optical brightness being proportional to the {gamma}-ray flux, and its passage through maximum not dependent on wavelength. The fact that {gamma}-rays are detected at a flux level that differs by four times from novae at the distance of the bulge seems to suggest that {gamma}-ray emission is not a widespread property of normal novae. We discuss the advantages offered by high-quality photometric observations collected with only one telescope (as opposed to data provided by a number of different instruments). We also observe the effects of the wavelength dependence of fireball expansion, the recombination in the flashed wind of a giant companion, the subtle presence of hiccups and plateaus, and the super-soft X-ray emission and its switch-off. Four programme novae (V2949 Oph, V3661 Oph, TCP J18102829-2729590 and ASASSN-16ma) have normal dwarf companions: V1534 Sco contains an M3 III giant, V1535 Sco a K-type giant and MASTER OT J010603.18-744715.8 a subgiant. We also comment briefly on the maximum absolute magnitude relation with decline time (MMRD).
- ID:
- ivo://CDS.VizieR/J/A+A/630/A75
- Title:
- Six luminous red novae photometry
- Short Name:
- J/A+A/630/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present extensive datasets for a class of intermediate-luminosity optical transients known as "luminous red novae" (LRNe). They show doublepeaked light curves, with an initial rapid luminosity rise to a blue peak (at -13 to -15mag), which is followed by a longer-duration red peak that sometimes is attenuated, resembling a plateau. The progenitors of three of them (NGC4490-2011OT1, M101-2015OT1, and SNhunt248), likely relatively massive blue to yellow stars, were also observed in a pre-eruptive stage when their luminosity was slowly increasing. Early spectra obtained during the first peak show a blue continuum with superposed prominent narrow Balmer lines, with P Cygni profiles. Lines of FeII are also clearly observed, mostly in emission. During the second peak, the spectral continuum becomes much redder, H{alpha} is barely detected, and a forest of narrow metal lines is observed in absorption. Very late-time spectra (~6 months after blue peak) show an extremely red spectral continuum, peaking in the infrared (IR) domain. H{alpha} is detected in pure emission at such late phases, along with broad absorption bands due to molecular overtones (such as TiO, VO). We discuss a few alternative scenarios for LRNe. Although major instabilities of single massive stars cannot be definitely ruled out, we favour a common envelope ejection in a close binary system, with possibly a final coalescence of the two stars. The similarity between LRNe and the outburst observed a few months before the explosion of the Type IIn SN 2011ht is also discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/625/L8
- Title:
- SN 2017jfs optical and NIR light curves
- Short Name:
- J/A+A/625/L8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our photometric and spectroscopic follow-up of the intermediate-luminosity optical transient AT 2017jfs. At peak, the object reaches an absolute magnitude of Mg=-15.46+/-0.15mag and a bolometric luminosity of 5.5x10^41^erg/s. Its light curve has the double-peak shape typical of luminous red novae (LRNe), with a narrow first peak bright in the blue bands, while the second peak is longer-lasting and more luminous in the red and near-infrared (NIR) bands. During the first peak, the spectrum shows a blue continuum with narrow emission lines of H and FeII. During the second peak, the spectrum becomes cooler, resembling that of a K-type star, and the emission lines are replaced by a forest of narrow lines in absorption. About 5 months later, while the optical light curves are characterized by a fast linear decline, the NIR ones show a moderate rebrightening, observed until the transient disappears in solar conjunction. At these late epochs, the spectrum becomes reminiscent of that of M-type stars, with prominent molecular absorption bands. The late-time properties suggest the formation of some dust in the expanding common envelope or an IR echo from foreground pre-existing dust. We propose that the object is a common-envelope transient, possibly the outcome of a merging event in a massive binary, similar to NGC4490-2011OT1.
