- ID:
- ivo://CDS.VizieR/J/other/JAD/15.1
- Title:
- Time-series of 9 cataclysmic variables
- Short Name:
- J/other/JAD/15.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present time-series photometry of nine cataclysmic variables: EI UMa, V844 Her, V751 Cyg, V516 Cyg, GZ Cnc, TY Psc, V1315 Aql, ASAS J002511+1217.2, V1315 Aql and LN UMa. The observations were conducted at various observatories, covering 170 hours and comprising 7850 data points in total. For the majority of targets we confirm previously reported periodicities and for some of them we give, for the first time through photometry, their underlying spectroscopic orbital period. For those dwarf-nova systems which we observed during both quiescence and outburst, the increase in brightness was accompanied by a decrease in the level of flickering. For the eclipsing system V1315 Aql we have covered 9 eclipses, and obtained a refined orbital ephemeris. We find that, during its long baseline of observations, no change in the orbital period of this system has occurred. V1315 Aql also shows eclipses of variable depth.
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- ID:
- ivo://CDS.VizieR/J/A+A/622/A126
- Title:
- T Pyx 2011 outburst optical spectra
- Short Name:
- J/A+A/622/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to study the spectroscopic and ionized structural evolution of T Pyx during its 2011 outburst, and also study the variation in degree of polarization during its early phase. Optical spectroscopic data of this system obtained from day 1.28-2415.62 since discovery, and optical, broadband imaging polarimetric observations obtained from day 1.36-29.33 during the early phases of the outburst were used in the study. The physical conditions and the geometry of the ionized structure of the nova ejecta was modelled for a few epochs using the photo-ionization code, CLOUDY in 1D and pyCloudy in 3D. The spectral evolution of the nova ejecta during its 2011 outburst is similar to that of the previous outbursts. The variation in the line profiles is seen very clearly in the early stages due to good coverage during this period. The line profiles vary from P Cygni (narrower, deeper, and sharper) to emission profiles that are broader and structured, which later become narrower and sharper in the late post-outburst phase. The average ejected mass is estimated to be 7.03x10^-6^M_{sun}_. The ionized structure of the ejecta is found to be a bipolar conical structure with equatorial rings, with a low inclination angle of 14.75+/-0.65{deg}.
- ID:
- ivo://CDS.VizieR/J/other/PZ/31.3
- Title:
- Two new cataclysmic variables in Lyra
- Short Name:
- J/other/PZ/31.3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I report on the discovery of two cataclysmic variables in the same field in Lyra, originally identified on the base of their magnitudes in the USNO-B1.0 catalog and on Palomar images. The historical light curves were analyzed from 300+ photographic plates of the Moscow collection, covering 35 years of observations. One of the two stars, USNO-B1.0 1320-0390658, is showing rather frequent outbursts from B~20 to B=15.2 and is likely a dwarf nova of the UGSS subtype. The other variable, USNO-B1.0 1321-0397655, with only one observed outburst in 1993, from B~19 to I=11.8, is either an UGWZ dwarf nova or a recurrent nova. In both cases, its next outburst can occur in the nearest future.
- ID:
- ivo://CDS.VizieR/J/AZh/80/535
- Title:
- UBV light curves of BE UMa
- Short Name:
- J/AZh/80/535
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBV photoelectric observations of BE Ursae Majoris, precataclysmic eclipsing variable with a strong reflection effect.
- ID:
- ivo://CDS.VizieR/J/A+A/604/A48
- Title:
- UBVRI photometry and line fluxes of AG Peg
- Short Name:
- J/A+A/604/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- AG Peg is known as the slowest symbiotic nova, which experienced its nova-like outburst around 1850. After 165 years, during June of 2015, it erupted again showing characteristics of the Z And-type outburst. The primary objective is to determine basic characteristics, the nature and type of the 2015 outburst of AG Peg. We achieved this aim by modelling the spectral energy distribution using low-resolution spectroscopy (330-750nm), medium-resolution spectroscopy (420-720nm; R=11000), and UBVR_C_I_C_ photometry covering the 2015 outburst with a high cadence. Optical observations were complemented with the archival HST and FUSE spectra from the preceding quiescence. During the outburst, the luminosity of the hot component was in the range of 2-11x10^37^(d/0.8kpc})^2^erg/s. To generate the maximum luminosity the white dwarf (WD) had to accrete at ~3x10^-7^M_{sun}/yr, which exceeds the stable-burning limit and thus led to blowing optically thick wind from the WD. We determined its mass-loss rate to a few x10^-6^M_{sun}/yr. At the high temperature of the ionising source, 1.5-2.3x10^5^K, the wind converted a fraction of the WD's photospheric radiation into the nebular emission that dominated the optical. A one order of magnitude increase of the emission measure, from a few x10^59^(d/0.8kpc)^2^/cm^3^ during quiescence, to a few x10^60^(d/0.8kpc)^2^/cm^3^ during the outburst, caused a 2mag brightening in the LC, which is classified as the Z And-type of the outburst. The very high nebular emission and the presence of a disk-like HI region encompassing the WD, as indicated by a significant broadening and high flux of the Raman-scattered OVI 6825{AA} line during the outburst, is consistent with the ionisation structure of hot components in symbiotic stars during active phases.
- ID:
- ivo://CDS.VizieR/J/A+A/317/712
- Title:
- UV fluxes and electron density of AG Peg
- Short Name:
- J/A+A/317/712
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we study in detail the variability of the symbiotic nova AG Peg in the IUE range during the period 1978-1995. We find that the luminosity of the hot component decreased steadily from about 1850L_{sun}_ in 1978 to 430L_{sun}_ in 1995 while its effective temperature remained nearly constant, 86500+/-1300K. At the same time, the mass loss rate decreased by a factor of 4-5 although the ejection velocity remained constant. The observed fainting of both the narrow and the broad emission lines is ascribed to the decrease of the luminosity and ionizing flux from the hot source. The narrow emission lines and the long wavelength UV continuum show periodic variations arising from a dense and asymmetric nebular region associated with the cool star. Radial velocity variations of the narrow lines indicate that this region is receding from the center of mass of the system, and support the presence of the ablation tail suggested by Penston and Allen (1985MNRAS.212..939P). No periodic flux variations are seen in the short wavelength ultraviolet continuum and in the broad emission lines, which are both formed in the fast wind from the hot component.
- ID:
- ivo://CDS.VizieR/J/A+A/560/A49
- Title:
- UV spectra of old novae
- Short Name:
- J/A+A/560/A49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an overview of the UV spectral properties of old novae as a class. The data and results of this paper, together with data from the outburst phases, will be utilized in a follow-up study to determine statistical properties and to investigate correlations among the physical parameters of the quiescent and eruptive phases.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/1061
- Title:
- Variability of FBS blue stellar objects
- Short Name:
- J/MNRAS/415/1061
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new method for combined calculations of magnitudes based on accurate measurements of POSS1 and POSS2 epoch plates is given. The photometric accuracy of various surveys and catalogs has been estimated and established and statistical weights for each of them have been calculated. To achieve the best possible magnitudes, weighted averaging of data from USNO-A2.0, APM, MAPS, USNO-B1.0, and GSC 2.3.2 catalogs have been used. The rms accuracy of magnitudes achieved for POSS1 is 0.184 mag for B and 0.173 mag for R and for POSS2 is 0.138 mag for B and 0.128 mag for R. We have derived the best POSS1 and POSS2 magnitudes for the FBS blue stellar objects. We have refined the transformation formulae between the POSS1 and POSS2 magnitudes and SDSS ones and standard UBV system. Using these accurate magnitudes, we have estimated the variability of the FBS blue stellar objects and revealed probable and possible variables. We have worked out methods to control and exclude accidental errors that appear in any survey. We have compared and combined our results with those given in NSVS database and obtained better candidates for variability. Having excluded variables, we have combined POSS1 and POSS2 data for the rest of objects to achieve even better magnitudes and colors; the rms being smaller than 0.1 mag both in B and R and for the B-R colors. This approach has been applied to the First Byurakan Survey blue stellar objects containing significant number of white dwarfs, cataclysmic variables, as well as extragalactic objects (quasars, Seyferts, BL Lac objects). Altogether 336 variable objects have been revealed with POSS2-POSS1 >= 3{sigma} of the errors. An electronic table of these objects is given. Candidate variables are divided into 4 classes: extreme, strong, probable and possible variables. For a more reliable sample of variable objects we excluded possible ones from the list and were left with 161 objects. Analyzing radio and X-ray properties of these objects, we have revealed their nature and re-discovered or revealed candidate AGN, CVs, WDs and other objects.
- ID:
- ivo://CDS.VizieR/J/A+A/265/77
- Title:
- VBLUW Observations of TT Ari
- Short Name:
- J/A+A/265/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- TT Ari was observed in the 5 passbands VBLUW (544, 430, 384, 362 and 324nm) during 3 nights on the 90cm telescope at ESO (La Silla), between July and November 1988, with an integration time of 16s.
- ID:
- ivo://CDS.VizieR/J/A+A/420/571
- Title:
- V1974 Cyg IUE spectroscopy
- Short Name:
- J/A+A/420/571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a detailed analysis of the IUE archival high resolution spectra of the classical nova V1974 Cyg 1992. The main UV resonance lines show P Cygni profiles in the first days, which change into symmetric pure emission lines, and then slowly become fainter and narrower. Lines of higher ionization species reach their peak luminosity later than those of low ionization.
