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- ID:
- ivo://CDS.VizieR/J/MNRAS/440/3402
- Title:
- Nova Cep 2013 (V809 Cep) UBVRI light curves
- Short Name:
- J/MNRAS/440/3402
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BVR_C_I_C_ photometry and low-, medium- and high-resolution echelle fluxed spectroscopy is presented and discussed for three faint, heavily reddened novae of the Feii-type which erupted in 2013. V1830 Nova Aql 2013 reached a peak V=15.2mag on 2013 Oct 30.3 UT and suffered from a huge E(B-V)~2.6mag reddening. After a rapid decline, when the nova was {Delta}V=1.7mag below maximum, it entered a flat plateau where it remained for a month until solar conjunction prevented further observations. Similar values were observed for V556 Nova Ser 2013, that peaked near R_C_~12.3 around 2013 Nov 25 and soon went lost in the glare of sunset sky. A lot more observations were obtained for V809 Nova Cep 2013, that peaked at V=11.18 on 2013 Feb 3.6. The reddening is E(B-V)~1.7 and the nova is located within or immediately behind the spiral Outer Arm, at a distance of ~6.5kpc as constrained by the velocity of interstellar atomic lines and the rate of decline from maximum. While passing at t_3_, the nova begun to form a thick dust layer that caused a peak extinction of {Delta}V>5mag, and took 125d to completely dissolve. The dust extinction turned from neutral to selective around 6000{AA}. Monitoring the time evolution of the integrated flux of emission lines allowed us to constrain the region of dust formation in the ejecta to be above the region of formation of OI 7774{AA} and below that of CaII triplet. Along the decline from maximum and before the dust obscuration, the emission line profiles of Nova Cep 2013 developed a narrow component (FWHM=210km/s) superimposed on to the much larger normal profile, making it a member of the so-far exclusive but growing club of novae displaying this peculiar feature. Constrains based on the optical thickness of the innermost part of the ejecta and on the radiated flux, place the origin of the narrow feature within highly structured internal ejecta and well away from the central binary.
- ID:
- ivo://CDS.VizieR/J/ApJ/795/8
- Title:
- Nova CI Aql MMO light curve data
- Short Name:
- J/ApJ/795/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Pre-outburst and post-outburst light curves and post-outburst eclipse timings are analyzed to measure any period (P) change related to nova CI Aql's outburst of early 2000 and a mean post-outburst dP/dt, which then lead to estimates of the accreting component's rate of mass (M) change and its overall outburst-related change of mass over roughly a decade of observations. We apply a recently developed procedure for unified analysis of three timing-related data types (light curves, radial velocities, and eclipse timings), although with only light curves and timings in this case. Fits to the data are reasonably good without need for a disk in the light-curve model, although the disk certainly exists and has an important role in our post-outburst mass flow computations. Initial experiments showed that, although there seems to be an accretion hot spot, it has essentially no effect on derived outburst-related {Delta}P or on post-outburst dP/dt. Use of atomic time (HJED) in place of HJD also has essentially nil effect on {Delta}P and dP/dt. We find {Delta}P consistently negative in various types of solutions, although at best only marginally significant statistically in any one experiment. Pre-outburst HJD_0_ and P results are given, as are post-outburst HJD_0_, P, and dP/dt, with light curves and eclipse times as joint input, and also with only eclipse time input. Post-outburst dP/dt is negative at about 2.4{sigma}. Explicit formulae for mass transfer rates and epoch-to-epoch mass change are developed and applied. A known offset in the magnitude zero point for 1991-1994 is corrected.
- ID:
- ivo://CDS.VizieR/J/A+A/580/A45
- Title:
- Nova M31N 2008-12a 2014 eruption in optical/UV
- Short Name:
- J/A+A/580/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Andromeda Galaxy recurrent nova M31N 2008-12a had been caught in eruption eight times. The inter-eruption period of M31N 2008-12a is ~1-year, making it the most rapidly recurring system known, and a strong single- degenerate Type Ia Supernova progenitor candidate. Following the 2013 eruption, a campaign was initiated to detect the predicted 2014 eruption and to then perform high cadence optical photometric and spectroscopic monitoring using ground-based telescopes, along with rapid UV and X-ray follow-up with the Swift satellite. Here we report the results of a high cadence multicolour optical monitoring campaign, the spectroscopic evolution, and the UV photometry. We also discuss tantalising evidence of a potentially related, vastly-extended, nebulosity. The 2014 eruption was discovered, before optical maximum, on October 2, 2014. We find that the optical properties of M31N 2008-12a evolve faster than all Galactic recurrent novae known, and all its eruptions show remarkable similarity both photometrically and spectroscopically. Optical spectra were obtained as early as 0.26-days post maximum, and again confirm the nova nature of the eruption. A significant deceleration of the inferred ejecta expansion velocity is observed which may be caused by interaction of the ejecta with surrounding material, possibly a red giant wind. We find a low ejected mass and low ejection velocity, which are consistent with high mass-accretion rate, high mass white dwarf, and short recurrence time models of novae. We encourage additional observations, especially around the predicted time of the next eruption, towards the end of 2015.
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/771
- Title:
- Nova Mon 2012 BV(RI)c light curves
- Short Name:
- J/MNRAS/435/771
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and discuss accurate and densely mapped BVR_C_I_C_ light curves of the neon Nova Mon 2012, supplemented by the evolution in Stromgren b and y bands and in the integrated flux of relevant emission lines. Our monitoring started with the optical discovery of the nova (50days past the first detection in gamma-rays by Fermi-LAT) and extend to day +270, well past the end of the super-soft phase in X-rays. The nova was discovered during the nebular decline, well past t_3_ and the transition to optically thin ejecta. It displayed very smoothly evolving light curves. A bifurcation between y and V light curves took place at the start of the super-soft X-ray source (SSS) phase, and a knee developed towards the end of the SSS phase. The apparent magnitude of the nova at the unobserved optical maximum is constrained to +3<=V<=4.5. The appearance, grow in amplitude and then demise of a 0.29585 (+/-0.00002) days orbital modulation of the optical brightness was followed along the nova evolution. The observed modulation, identical in phase and period with the analogue seen in the X-ray and satellite ultraviolet, has a near-sinusoidal shape and a weak secondary minimum at phase 0.5. We favour an interpretation in terms of super-imposed ellipsoidal distortion of the Roche lobe filling companion and irradiation of its side facing the WD. Similar light curves are typical of symbiotic stars where a Roche lobe filling giant is irradiated by a very hot WD. Given the high orbital inclination, mutual occultation between the donor star and the accretion disc could contribute to the observed modulation. The optical+infrared spectral energy distribution of Nova Mon 2012 during the quiescence preceding outburst is nicely fitted by an early K-type main-sequence star (~K3V) at 1.5kpc distance, reddened by E(B-V)=0.38, with a WD companion and an accretion disc contributing to the observed blue excess and moderate H{alpha} emission. A typical early K-type main-sequence star with a mass of ~0.75M_{sun}_ and a radius of ~0.8 R{sun} would fill its Roche lobe for a P=0.29585d orbital period and a more massive WD companion (as implied by the large Ne overabundance of the ejecta).
- ID:
- ivo://CDS.VizieR/J/AJ/99/1079
- Title:
- Nova rate in NGC 5128
- Short Name:
- J/AJ/99/1079
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a five year nova survey of NGC 5128 performed with an H{alpha} filter at the prime focus of the CTIO 4m telescope. In all, 16 novae were detected, of which 12 are members of a statistically complete and homogeneous sample unaffected by the absorption lane of the galaxy. When normalized to B luminosity, the nova rate in the elliptical component of NGC 5128 is 2.7+/-1.0 times less than that observed in the bulge of M 31. However, when normalized in the infrared K bandpass, the two nova rates are identical, and comparable to that measured in the Large Magellanic Cloud. These data suggest that (1) the percentage of binary stars is approximately constant over a large range of star-forming environments, (2) the nova rate in our own galaxy is between 11 and 46yr^-1^ , and (3) nova rates are not strongly affected by tidal captures in bright globular clusters.
- ID:
- ivo://CDS.VizieR/J/other/CoSka/39.43
- Title:
- Nova Tri UBV(RI)c light curves
- Short Name:
- J/other/CoSka/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the UBV(RI)c photometry of the dwarf nova Tri 2008 = OT J023839.1+355648 obtained during its superoutburst started on October 25, 2008. The object can be classified as a WZ Sge-type dwarf nova. The period of early superhumps 0.05307 days was detected in the first 7 days of the superoutburst. The period of ordinary superhumps 0.053663 days, detected in days 8-23 of the superoutburst, is the shortest one among WZ Sge-type objects. After one month, the dwarf nova returned to its pre-outburst state. A sudden increase of activity of the object during its quiescent stage was detected on January 11, 2009.
- ID:
- ivo://CDS.VizieR/J/A+A/543/A86
- Title:
- Nova V1280 Sco BVRcIcy light curves
- Short Name:
- J/A+A/543/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical (B, V, Rc, Ic and y) and near-infrared (J, H, and Ks) photometric and spectroscopic observations of a classical nova V1280 Scorpii for five years from 2007 to 2011. Our photometric observations show a declining event in optical bands shortly after the maximum light, which took about 250 days to recover. This event was most probably caused by dust formation. The event was accompanied by a short (~30 days) re-brightening episode (~2.5mag in V), which suggests that there had been some re-ignition of the surface nuclear burning. After 2008, the y band observations show a very long plateau at around y=10.5 for more than 1000 days until April 2011 (~1500 days after the maximum light). The nova had taken a very long time (~50 months) to enter the nebular phase, according to a clear detection of both [OIII] 4959 and 5007 and is still continuing to generate the wind caused by H-burning. This finding suggests that historically V1280 Sco is evolving at its slowest ever measured rate. The interval from the maximum light (2007 February 16) to the beginning of the nebular phase is longer than any previously known slow novae: V723 Cas (18 months), RR Pic (10 months), or HR Del (8 months). It suggests that the mass of a white dwarf in the V1280 Sco system might be 0.6M_{sun}_ or lower. The distance, based on our measurements of the expansion velocity combined with the directly measured size of the dust shell, is estimated to be 1.1+/-0.5kpc.
- ID:
- ivo://CDS.VizieR/J/AcA/64/197
- Title:
- OGLE-IV 2012-2014 transients
- Short Name:
- J/AcA/64/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the design and first results of a real-time search for transients within the 650 sq. deg. area around the Magellanic Clouds, conducted as part of the OGLE-IV project and aimed at detecting supernovae, novae and other events. The average sampling of about four days from September to May, yielded a detection of 238 transients in 2012/2013 and 2013/2014 seasons. The superb photometric and astrometric quality of the OGLE data allows for numerous applications of the discovered transients. We use this sample to prepare and train a Machine Learning-based automated classifier for early light curves, which distinguishes major classes of transients with more than 80% of correct answers. Spectroscopically classified 49 supernovae Type Ia are used to construct a Hubble Diagram with statistical scatter of about 0.3mag and fill the least populated region of the redshifts range in the Union sample. We investigate the influence of host galaxy environments on supernovae statistics and find the mean host extinction of A_I_=0.19+/-0.10mag and A_V_=0.39+/-0.21mag based on a subsample of supernovae Type Ia. We show that the positional accuracy of the survey is of the order of 0.5pixels (0.13") and that the OGLE-IV Transient Detection System is capable of detecting transients within the nuclei of galaxies. We present a few interesting cases of nuclear transients of unknown type. All data on the OGLE transients are made publicly available to the astronomical community via the OGLE website.
- ID:
- ivo://CDS.VizieR/J/AcA/65/313
- Title:
- One thousand new dwarf novae from the OGLE Survey
- Short Name:
- J/AcA/65/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present one of the largest collections of dwarf novae (DNe) containing 1091 objects that have been discovered in the long-term photometric data from the Optical Gravitational Lensing Experiment (OGLE) survey. They were found in the OGLE fields toward the Galactic bulge and the Magellanic Clouds. We analyze basic photometric properties of all systems and tentatively find a population of DNe from the Galactic bulge. We identify several dozen of WZ Sge-type DN candidates, including two with superhump periods longer than 0.09d. Other interesting objects include SU UMa-type stars with "early" precursor outbursts or a Z Cam-type star showing outbursts during standstills. We also provide a list of DNe which will be observed during the K2 Campaign 9 microlensing experiment in 2016. Finally, we present the new OGLE-IV real-time data analysis system: CVOM, which has been designed to provide continuous real time photometric monitoring of selected CVs.
