- ID:
- ivo://CDS.VizieR/J/A+A/326/1044
- Title:
- Eclipsing binaries uvbyHbeta photometry
- Short Name:
- J/A+A/326/1044
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Systematic differences in photometric stellar surface gravity determination are studied by means of the comparison with empirical values derived from detached double-lined eclipsing binaries. Photometric gravities were computed using Moon & Dworetsky (1985MNRAS.217..305M) grids based on Kurucz (1979ApJS...40....1K) atmosphere models, and empiric al gravities were taken from Andersen (1991A&ARv...3...91A). Individual Stroemgren colours and {beta} indices of each component of the binary system have to be taken into account to correctly analyze the observed differences. A compilation of data on a sample containing 30 detached double-lined eclipsing binaries with accurate (=~1-2%) determination of mass and radius and available uvbyH_{beta}_ photometric data is also presented. Correction of the differences in terms of T_eff_ and logg for the range 11000K<T_eff_<20000K reduces the mean residuals from 0.13dex to 0.07dex. For the range 7000K<T_eff_<8500K, the consideration of metallicity effects by means of {delta}m_o_ index improves the accuracy from 0.20dex to 0.09dex.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/324/137
- Title:
- Eclipsing binaries with candidate CP stars
- Short Name:
- J/A+A/324/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometry in the Geneva systems and radial velocities are used to determine the fundamental parameters of three eclipsing binaries, two of which having been classified as chemically peculiar and the third having relatively narrow lines. For a description of the Geneva photometric system, see e.g. <GCPD/13>
- ID:
- ivo://CDS.VizieR/J/ApJ/831/L6
- Title:
- Eclipsing binary parallaxes with Gaia data
- Short Name:
- J/ApJ/831/L6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We test the parallaxes reported in the Gaia first data release using the sample of eclipsing binaries with accurate, empirical distances from Stassun & Torres (2016, arXiv:1609.02579). We find an average offset of -0.25+/-0.05mas in the sense of the Gaia parallaxes being too small (i.e., the distances too long). The offset does not depend strongly on obvious parameters such as color or brightness. However, we find with high confidence that the offset may depend on ecliptic latitude: the mean offset is -0.38+/-0.06mas in the ecliptic north and -0.05+/-0.09mas in the ecliptic south. The ecliptic latitude dependence may also be represented by the linear relation, {Delta}{pi}~-0.22(+/-0.05)-0.003(+/-0.001)x{beta}mas ({beta} in degrees). Finally, there is a possible dependence of the parallax offset on distance, with the offset becoming negligible for {pi}<~1mas; we discuss whether this could be caused by a systematic error in the eclipsing binary distance scale, and reject this interpretation as unlikely.
- ID:
- ivo://CDS.VizieR/J/A+A/557/A13
- Title:
- 3 eclipsing high-mass binaries light curve
- Short Name:
- J/A+A/557/A13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results of a comprehensive photometric O-star survey performed with a robotic twin refractor at the Universitatssternwarte Bochum located near Cerro Armazones in Chile. For three high-mass stars, Pismis 24-1, CPD-51 8946, and HD 319702, we determined the period through the Lafler-Kinman algorithm and modelled the light curves within the framework of the Roche geometry.
- ID:
- ivo://CDS.VizieR/J/ApJ/831/89
- Title:
- Eclipsing LMXB at the center of 3FGL J0427.9-6704
- Short Name:
- J/ApJ/831/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of an eclipsing low-mass X-ray binary at the center of the 3FGL error ellipse of the unassociated Fermi/Large Area Telescope {gamma}-ray source 3FGL J0427.9-6704. Photometry from OGLE and the SMARTS 1.3m telescope and spectroscopy from the SOAR telescope have allowed us to classify the system as an eclipsing low-mass X-ray binary (P=8.8hr) with a main-sequence donor and a neutron-star accretor. Broad double-peaked H and He emission lines suggest the ongoing presence of an accretion disk. Remarkably, the system shows separate sets of absorption lines associated with the accretion disk and the secondary, and we use their radial velocities to find evidence for a massive (~1.8-1.9M_{sun}_) neutron-star primary. In addition to a total X-ray eclipse with a duration of ~2200s observed with NuSTAR, the X-ray light curve also shows properties similar to those observed among known transitional millisecond pulsars: short-term variability, a hard power-law spectrum ({Gamma}~1.7), and a comparable 0.5-10keV luminosity (~2.4x10^33^erg/s). We find tentative evidence for a partial (~60%) {gamma}-ray eclipse at the same phase as the X-ray eclipse, suggesting the {gamma}-ray emission may not be confined to the immediate region of the compact object. The favorable inclination of this binary is promising for future efforts to determine the origin of {gamma}-rays among accreting neutron stars.
- ID:
- ivo://CDS.VizieR/J/A+A/492/637
- Title:
- Eddington ratios of faint AGN
- Short Name:
- J/A+A/492/637
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use one of the deepest spectroscopic samples of broad-line active galactic nuclei (AGN) currently available, extracted from the VIMOS VLT Deep Survey (VVDS, Cat. <III/250>), to compute the MgII and CIV virial-mass estimates of 120 super-massive black holes in the redshift range 1.0<z<1.9 and 2.6<z<4.3.
- ID:
- ivo://CDS.VizieR/J/AJ/162/11
- Title:
- EDEN project: Flare activity of nearby M-dwarf Wolf 359
- Short Name:
- J/AJ/162/11
- Date:
- 16 Mar 2022 00:09:17
- Publisher:
- CDS
- Description:
- We report the flare activity of Wolf359, the fifth closest star to the Sun and a candidate exoplanet-hosting M-dwarf. The star was a target of the Kepler/K2 mission and was observed by the EDEN project, a global network of 1-2m class telescopes for detection and characterization of rocky exoplanets in the habitable zones of late M-dwarfs within 50 light year from the solar system. In the combination of the archived K2 data and our EDEN observations, a total of 872 flares have been detected, 861 with the K2 (860 in the short-cadence and 18 in the long-cadence data, with 17 long-cadence events having short-cadence counterparts) and 11 with EDEN. Wolf 359 has relatively strong flare activity even among flaring M-dwarfs, in terms of the flare activity indicator (FA) defined as the integrated flare energy relative to the total stellar bolometric energy, where FA={sum}E_f_/{int}L_bol_dt~8.93x10^-5^ for the long-cadence flares, whereas for K2 short cadence and EDEN flares, the FA values are somewhat larger, FA~6.67 x 10^-4^ and FA~5.25x10^-4^, respectively. Such a level of activity, in accordance with the rotation period (P_rot_), suggests the star to be in the saturation phase. The size of the starspots is estimated to be at least 1.87%{+/-}0.59% of the projected disk area of Wolf359. We find no correlation of FA with the stellar rotational phase. Our analysis indicates a flare frequency distribution in a power-law form of dN/dE{prop}E^-{alpha}^ with {alpha}=2.13{+/-}0.14, equivalent to an occurrence rate of flares E_f_>~10^31^erg about once per day and of superflares with E_f_>~10^33^erg approximately 10 times per year. These superflares may impact the habitability of system in multiple ways, the details of which are topics for future investigations.
- ID:
- ivo://CDS.VizieR/J/ApJS/248/33
- Title:
- Edge-on HI-rich LSB galaxies from ALFALFA
- Short Name:
- J/ApJS/248/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Low surface brightness galaxies (LSBGs) are defined as galaxies that are fainter than dark night sky and are important for studying our universe. Particularly, edge-on galaxies are useful for the study of rotational velocity and dynamical properties of galaxies. Hence here we focus on searching for edge-on LSBGs. In order to find these edge-on dim galaxies, a series of effects caused by inclination, including the surface brightness profile, internal extinction, and scale length, have been corrected. In this work, we present a catalog of 281 edge-on LSBG candidates, which are selected from the crossmatch between Sloan Digital Sky Survey Data Release 7 and the 40% ALFALFA catalog. We also present the properties of these edge-on LSBG candidates including the absolute magnitude, central surface brightness, B-V color, scale length, and relative thickness. Our result suggests that the correction of inclination effects is very important for obtaining a complete sample of LSBGs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/431/240
- Title:
- Edinburgh-Cape Blue Object Survey. III.
- Short Name:
- J/MNRAS/431/240
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Edinburgh-Cape Blue Object Survey seeks to identify point sources with an ultraviolet excess. Results for zone 2 of the survey are presented here, covering that part of the South Galactic Cap between 30 and 40{deg} from the Galactic plane and south of about -12.3{deg} of declination. Edinburgh-Cape zone 2 comprises 66 UK Schmidt Telescope fields covering about 1730sq.deg, in which we find some 892 blue objects, including 423 hot subdwarfs (~47%); 128 white dwarfs (14%); 25 cataclysmic variables (~3%); 119 binaries (~13%), mostly composed of a hot subdwarf and a main-sequence F or G star; 66 horizontal branch stars (~7%) and 48 "star-like" extragalactic objects (~5%). A further 362 stars observed in the survey, mainly low-metallicity F- and G-type stars, are also listed. Both low-dispersion spectroscopic classification and UBV photometry are presented for almost all of the hot objects and either spectroscopy or photometry (or both) for the cooler ones.
- ID:
- ivo://CDS.VizieR/J/MNRAS/287/867
- Title:
- Edinburgh-Cape Blue Object Survey. Zone 1.
- Short Name:
- J/MNRAS/287/867
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results for Zone 1 of the Edinburgh-Cape (EC) Blue Object Survey are presented. This zone covers that part of the North Galactic Cap more than ~30{deg} from the Galactic plane and south of about -12.3{deg} declination (although a few fields north of this declination are included). The zone effectively complements the Palomar-Green Survey in the North Galactic Cap, although the EC Survey should be more complete to a fainter limit (B=16.5mag) and to somewhat redder stars (U-B bluer than about -0.4). Zone 1 covers approximately 1560{deg}^2^ and contains 675 blue objects far which we list equatorial coordinates accurate to ~1arcsec, UBV photoelectric photometry, and spectral types determined from moderate-dispersion (100{AA}/mm) spectrograms.
