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- ID:
- ivo://CDS.VizieR/J/A+A/386/237
- Title:
- UBV(RI)c photometry of 7 symbiotic stars
- Short Name:
- J/A+A/386/237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Asiago photographic archive has been searched for plates containing the symbiotic stars Hen 2-468, QW Sge, LT Del, V407 Cyg, K 3-9, V335 Vul, FG Ser and Draco C-1. A total of 635 plates imaging the program stars have been found and the brightness estimated using the Henden & Munari (2000A&AS..143..343H) UBV(RI) photometric sequences. These historical data have allowed for the first time the determination of the orbital periods of Hen 2-468 (774 days) and QW Sge (390.5 days), a significant improvement in the orbital period of LT Del (465.6 days) and for V407 Cyg an evaluation of the Mira's pulsation period and complex lightcurve shape in the red (R and I bands). Some previously unknown outbursts have been discovered too.
- ID:
- ivo://CDS.VizieR/J/A+A/469/1033
- Title:
- UBVRI light curves of RR Gem
- Short Name:
- J/A+A/469/1033
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RR Gem is one of the few Blazhko RR Lyrae which has extended enough photometric observations available to study the long-term courses of its pulsation and modulation properties in detail. We investigate the pulsation and modulation properties and the relations between them in RR Gem using the last 70 years' photometric observations in order to gain further insight into the nature of the Blazhko modulation. Photographic, photoelectric and CCD light curves obtained at the Konkoly Observatory and other authors' published maxima observations are studied. Detailed analysis of the light curves, maximum brightness and O-C data are carried out.
- 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/503/1023
- Title:
- Variability Sample Catalogue from SOGS
- Short Name:
- J/A+A/503/1023
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A set of 55000 stars brighter than about B-magnitude 14 and having at least three observations are identified in the Sydney Observatory Galactic Survey, carried out over the years 1892-1932 along the galactic equator section l{in}[275deg,335deg] with galactic latitude b{in}[-7deg,7deg]. Short-term (30min) and long-term (decades) magnitude variations in the data set are analyzed.
- ID:
- ivo://CDS.VizieR/J/ApJ/87/361
- Title:
- Variable stars in M92
- Short Name:
- J/ApJ/87/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The distance modulus of M92 is determined from the bright stars and the mean magnitude of 12 cluster-type variables. From the former, m-M=14.93; and from the latter, m-M=14.94+/-0.01. Two variables not belonging to the cluster are indicated, as well as two other stars with range in variation of 0.25mag, which are marked as probable variables. From star counts, the ratio of the minor to the major axis is found to be 0.85, with a position angle of the major axis of 28{deg}. Sensitometer tracings give 14' for the diameter of the cluster.
- ID:
- ivo://CDS.VizieR/II/320
- Title:
- Variable stars in the M16-M17 field
- Short Name:
- II/320
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The original work was published as a paper book by the Perugia University in 1999. Before that, only the variable stars list (coordinates, classifications, periods, epochs, magnitude ranges) was published (P. Maffei, 1975IBVS..985....1M) The photographic material was discontinuously collected with the two Schmidt telescopes of the Asiago Observatory and with the Schmidt telescope of the Catania Astrophysical Observatory in the years 1961 to 1991. 103a-O without or with filter GG13 and hypersensitized with NH3 or pre-flashed I-N+RG5 were used. Date, JD, exposure time, emulsion/filter combination and the observer for each plate are listed in Table 1 and Table 2. The variable search was carried out with the blink microscope plate comparator of the Asiago Observatory. Details about the history and the reduction of the observational material are given in the "main.htm" file; the digitization was made by Alessandro Nesci.
- ID:
- ivo://CDS.VizieR/J/A+A/636/A77
- Title:
- V426 Sagittae (HBHA 1704-05) light curves
- Short Name:
- J/A+A/636/A77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The star V426 Sge (HBHA 1704-05), originally classified as an emission-line object and a semi-regular variable, brightened at the beginning of August 2018, showing signatures of a symbiotic star outburst. We aim to confirm the nature of V426 Sge as a classical symbiotic star, determine the photometric ephemeris of the light minima, and suggest the path from its 1968 symbiotic nova outburst to the following 2018 Z And-type outburst. We re-constructed an historical light curve (LC) of V426 Sge from approximately the year 1900, and used original low- (R~500-1500; 330-880nm) and high-resolution (R~11000-34000; 360-760nm) spectroscopy complemented with Swift-XRT and UVOT, optical UBVR_C_I_C_ and near-infrared $JHKL$ photometry obtained during the 2018 outburst and the following quiescence. The historical LC reveals no symbiotic-like activity from ~1900 to 1967. In 1968, V426 Sge experienced a symbiotic nova outburst that ceased around 1990. From approximately 1972, a wave-like orbitally related variation with a period of 493.4+/-0.7-days developed in the LC. This was interrupted by a Z And-type outburst from the beginning of August 2018 to the middle of February 2019. At the maximum of the 2018 outburst, the burning white dwarf (WD) increased its temperature to >~2x10^5^K, generated a luminosity of ~7x10^37^(d/3.3kpc}^2^erg/s, and blew a wind at the rate of ~3x10^-6^M_{sun}_/yr. Our spectral energy distribution models from the current quiescent phase reveal that the donor is a normal M4-5 III giant characterised with Teff~3400K, R_G_~106(d/3.3kpc})R_{sun}_ and L_G_~1350(d/3.3kpc})^2^L_{sun}_ and the accretor is a low-mass ~0.5M_{sun}_ WD. During the transition from the symbiotic nova outburst to the quiescent phase, a pronounced sinusoidal variation along the orbit develops in the LC of most symbiotic novae. The following eventual outburst is of Z And-type, when the accretion by the WD temporarily exceeds the upper limit of the stable burning. At this point the system becomes a classical symbiotic star.
- ID:
- ivo://CDS.VizieR/J/A+A/443/103
- Title:
- X-ray properties of NGC 300. I.
- Short Name:
- J/A+A/443/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- X-ray properties of NGC 300 point sources, extracted from 66ks of XMM-Newton data taken in 2000 December and 2001 January. A total of 163 sources were detected in the energy range of 0.3-6kev. We report on the global properties of the sources detected inside the D_25_ optical disk, such as the hardness ratio and X-ray fluxes, and on the properties of their optical counterparts found in B, V, and R images from the 2.2m MPG/ESO telescope. Furthermore, we cross-correlate the X-ray sources with SIMBAD, the USNO-A2.0 catalog, and radio catalogues.
