A catalogue of eclipsing variables
A new catalogue of 6330 eclipsing variable stars is presented. Thecatalogue was developed from the General Catalogue of Variable Stars(GCVS) and its textual remarks by including recently publishedinformation about classification of 843 systems and making correspondingcorrections of GCVS data. The catalogue1 represents thelargest list of eclipsing binaries classified from observations.
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Speckle interferometry of nearby multiple stars. III.
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Speckle Observations of Binary Stars with a 0.5 m Telescope
We present 36 observations of 17 visual binaries of moderate separation(ranging from 0.15" to 0.790") made with the 50 cm Cassegrain telescopeof the Jagiellonian University in Kraków. The speckleinterferometry technique was combined with modest optical hardware and astandard photometric CCD camera. We used broadband VRI filters without aRisley prism to reduce differential color refraction. Thus, we performeda model analysis to investigate the influence of this effect on theresults of the measurements. For binary components of spectral type O-F,the difference of three spectral classes between them should bias theirrelative positions by no more than a couple of tens of milliarcseconds(mas) for moderate zenith distances. The statistical analysis of ourresults confirmed this conclusion. A cross-spectrum approach was appliedto resolve the quadrant ambiguity. Our separations have rms deviationsof 0.012", and our position angles have rms deviations of 1.8d. Relativephotometry in V, R, and I filters appeared to be the less accuratelydetermined parameter. We discuss our errors in detail and compare themto other speckle data. This comparison clearly shows the quite goodaccuracy of our measurements. We also present an example of theenhancement of image resolution for an extended object with an angularsize that is greater than the atmospheric coherence patch, using speckleinterferometry techniques.
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Differential photometry of speckle-interferometric binary and multiple stars
A method for differential photometry of speckle-interferometric binaryand multiple stars is presented. Both the accuracy and sources ofsystematic errors of the method are analysed. The photometric accuracyranges between 0.02 m and 0.20 m, depending on the atmospheric seeing,the brightness and the separation of the system components. A comparisonbetween our magnitude differences and those of other authors ispresented.
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Photoelectric Minima of Some Eclipsing Binary Stars
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Speckle interferometry of nearby multiple stars. II.
This paper is a continuation of diffraction-limited speckleinterferometry of binary and multiple stars carried out at the 6-mtelescope of the Special Astrophysical Observatory in Zelenchuk. Theprogram has concentrated on nearby (π>10 mas) close binariesdiscovered or measured during the Hipparcos mission. Here, we present132 measurements of relative positions and magnitude differences for 99pairs and 8 measurements for 6 triple systems. 54 entries in the paperare new Hipparcos binaries. New triple systems with late-type dwarfcomponents, discovered in the course of observations, are HIP 8533 andHIP 25354.Based on data collected at the Special Astrophysical Observatory,Russia.{Tables 1-3 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?/A+A/422/627
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V1154 Tau: a New Eclipsing Star within a Triple System
V1154 Tau has been discovered by Hipparcos as a a low amplitude variableof unsolved nature. We have carried out extensive B,V photometry fromDec 2002 to February 2003 and discovered that V1154 Tau is an eclipsingsystem with an orbital period of 1.7678805 days. The system is triplewith the third component on an extremely wide orbit, 0.355 arcsec away,or 90 AU at the system distance, contributing 21 of the total systemlight. The orbit of the eclipsing binary is eccentric and the totalcolor difference between primary and secondary eclipse is 0.02 mag inB-V, both being total with flat bottom.
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Overlapping Open Clusters NGC 1750 and NGC 1758 Behind the Taurus Dark Clouds. II. CCD Photometry in the Vilnius System
Seven-color photometry in the Vilnius system has been obtained for 420stars down to V = 16 mag in the area containing the overlapping openclusters NGC 1750 and NGC 1758 in Taurus. Spectral and luminosityclasses, color excesses, interstellar extinctions and distances aregiven for 287 stars. The classification of stars is based on theirreddening-free Q-parameters. 18 stars observed photoelectrically wereused as standards. The extinction vs. distance diagram exhibits thepresence of one dust cloud at a distance of 175 pc which almostcoincides with a distance of other dust clouds in the Taurus complex.The clusters NGC 1750 and NGC 1758 are found to be at the same distanceof ~ 760 pc and may penetrate each other. Their interstellarextinction A_V is 1.06 mag which corresponds to EB-V = 0.34mag.
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New periodic variables from the Hipparcos epoch photometry
Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.
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H I Spectra and Column Densities toward HVC and IVC Probes
We show 21 cm line profiles in the direction of stars and extragalacticobjects, lying projected on high- and intermediate-velocity clouds (HVCsand IVCs). About half of these are from new data obtained with theEffelsberg 100 m telescope, about a quarter are extracted from theLeiden-Dwingeloo Survey (LDS), and the remaining quarter were observedwith other single-dish telescopes. H I column densities were determinedfor each HVC/IVC. Paper I of this series uses these in combination withoptical and ultraviolet high-resolution measurements to deriveabundances. Here an analysis is given of the difference and ratio of N(HI) as observed with a 9' versus a 35' beam. For HVCs and IVCs the ratioN(H I-9')/N(H I-35') lies in the range 0.2-2.5. For low-velocity gasthis ratio ranges from 0.75 to 1.3 (the observed ratio is 0.85-1.4, butit appears that the correction for stray radiation is slightly off). Thesmaller range for the low-velocity gas may be caused by confusion in theline of sight, so that a low ratio in one component can be compensatedby a high ratio in another-for 11 low-velocity clouds fitted by onecomponent the distribution of ratios has a larger dispersion. Comparisonwith higher angular resolution data is possible for 16 sight lines.Eight sight lines with H I data at 1'-2' resolution show a range of0.75-1.25 for N(H I-2')/N(H I-9'), while in eight other sight lines N(HI-Lyα)/N(H I-9') ranges from 0.74 to 0.98.
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Distances and Metallicities of High- and Intermediate-Velocity Clouds
A table is presented that summarizes published absorption linemeasurements for the high- and intermediate-velocity clouds (HVCs andIVCs). New values are derived for N(H I) in the direction of observedprobes, in order to arrive at reliable abundances and abundance limits(the H I data are described in Paper II). Distances to stellar probesare revisited and calculated consistently, in order to derive distancebrackets or limits for many of the clouds, taking care to properlyinterpret nondetections. The main conclusions are the following. (1)Absolute abundances have been measured using lines of S II, N I, and OI, with the following resulting values: ~0.1 solar for one HVC (complexC), ~0.3 solar for the Magellanic Stream, ~0.5 solar for a southern IVC,and ~solar for two northern IVCs (the IV Arch and LLIV Arch). Finally,approximate values in the range 0.5-2 solar are found for three moreIVCs. (2) Depletion patterns in IVCs are like those in warm disk or halogas. (3) Most distance limits are based on strong UV lines of C II, SiII, and Mg II, a few on Ca II. Distance limits for major HVCs aregreater than 5 kpc, while distance brackets for several IVCs are in therange 0.5-2 kpc. (4) Mass limits for major IVCs are0.5-8×105 Msolar, but for major HVCs theyare more than 106 Msolar. (5) The Ca II/H I ratiovaries by up to a factor 2-5 within a single cloud, somewhat morebetween clouds. (6) The Na I/H I ratio varies by a factor of more than10 within a cloud, and even more between clouds. Thus, Ca II can beuseful for determining both lower and upper distance limits, but Na Ionly yields upper limits.
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Speckle observations of binary systems measured by Hipparcos
From speckle observations made with the PISCO speckle camera at the Picdu Midi Observatory, we present high angular resolution astrometric datafor 43 binary stars already observed by the Hipparcos satellite. Thissample consists of mainly new Hipparcos eclipsing binaries with a visualcompanion closer than one arcsecond, chosen with the aim to study thedynamical implications of a third component on the observationalparameters of the eclipsing system. In addition, we also included aselection of close visual binaries with few speckle data in order toanalyse possible systematic departures between the speckle and thenon-speckle orbits. The reduction method and the results are presentedin detail. For the close visual binaries we confront our observationswith the ephemerides based on the best known orbits. For the wide visualbinaries the confrontation is made directly with the Hipparcos data. Ourobservations are consistent both with previous speckle data and withmost of the Hipparcos measurements. Based on observations made with theTélescope Bernard Lyot at the Pic du Midi Observatory, France andon data obtained by the Hipparcos astrometry satellite. This work hasalso made use of the Simbad database, operated at CDS, Strasbourg,France.
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Binary star speckle measurements at Calar Alto. I.
We present the first results of our speckle interferometric measurementsof binary stars made with the ICCD speckle camera using the 1.52-mtelescope of the Observatorio Astronomico Nacional at Calar Alto (Spain)in September, 1999. The data contain 123 observations of 83 systems. Themeasured angular separations range from 0farcs153 to 6farcs727 . We haveused there new speckle measurements to improve the orbital elements forthe binaries COU 247 and BU 524 AB.
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Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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ICCD Speckle Observations of Binary Stars. XXIII. Measurements during 1982-1997 from Six Telescopes, with 14 New Orbits
We present 2017 observations of 1286 binary stars, observed by means ofspeckle interferometry using six telescopes over a 15 year period from1982 April to 1997 June. These measurements constitute the 23dinstallment in CHARA's speckle program at 2 to 4 m class telescopes andinclude the second major collection of measurements from the MountWilson 100 inch (2.5 m) Hooker Telescope. Orbital elements are alsopresented for 14 systems, seven of which have had no previouslypublished orbital analyses.
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Two-colour photometry for 9473 components of close Hipparcos double and multiple stars
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
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Binary star speckle measurements during 1992-1997 from the SAO 6-m and 1-m telescopes in Zelenchuk
We present the results of speckle interferometric measurements of binarystars made with the television photon-counting camera at the 6-m BigAzimuthal Telescope (BTA) and 1-m telescope of the Special AstrophysicalObservatory (SAO) between August 1992 and May 1997. The data contain 89observations of 62 star systems on the large telescope and 21 on thesmaller one. For the 6-m aperture 18 systems remained unresolved. Themeasured angular separation ranged from 39 mas, two times above the BTAdiffraction limit, to 1593 mas.
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Hipparcos: The Stars
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The 74th Special Name-list of Variable Stars
We present the Name-list introducing GCVS names for 3153 variable starsdiscovered by the Hipparcos mission.
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A Search for Star Clusters from the HIPPARCOS Data
We present results of a search for nearby star clusters and associationsusing Hipparcos Catalogue data, restricting the sample to stars withparallaxes above 2 mas (d <~ 500 pc). Two new OB associations havebeen identified in the Carina-Vela and Cepheus-Cygnus-Lyra-Vulpecularegions. A very probable new open cluster has been discovered in Carina.The cluster, a Car, named after its brightest member, is young (60 Myr)and nearby (d = 132 pc). However, only seven bona fide members can bedrawn from the Hipparcos data. We report a detection of nine opencluster candidates in the distance range of 150 to 400 pc, and sixpossible associations almost all located within the Gould belt, althoughslightly older than the known nearby associations. In all cases, wepresent Yale theoretical isochrone fits to the color-magnitude diagrams,which indicate a moderate spread of ages between 60 to 200 Myr.Evidently, these young open cluster and association candidates arerelated to the overall distribution of young OB and A-type stars in thesolar neighborhood.
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Measurements of double stars 1993.67 - 1998.13
624 Micrometer Measurements of 224 pairs with a 32.5 cm Cassegrain, 719Measurements of 310 double stars with a 360 mm Newtonian are given.Tables 1 to 4 are available in electronic form only at the CDS130.79.128.5 or via http://cdsweb.u-strasbg.fr/Abstract.html
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The overlapping open clusters NGC 1750 and NGC 1758. II. $\vec BVR photographic photometry and proper motions
Astrometry (positions and proper motions) and photographic BVRphotometry were determined from a set of 29 photographic plates and CCDdata in a region of 2.3(deg}x2.3({deg)) in the area of open clusters NGC1750 and NGC 1758 in Taurus. The iterative central overlap algorithm wasused for the proper motion calculations. Plate-to-plate transformationsand astrometric magnitude effects are discussed in detail. CCD datainteract with photographic material in three different ways: for theelimination of astrometric magnitude effects, for the photometricstandard calibration of photographic plates and for building a CCDpseudo-plate used for astrometric purposes as any other photographicplate. A preliminary analysis of the resulting photometric andastrometric catalogue confirmed the reality of two different clusters inthe zone (NGC 1750 and NGC 1758). There were no indications for theexistence of NGC 1746. Tables 6 and 11 are only available in electronicform from CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) orvia http://cdsweb.u-strasbg.fr/Abstract.html
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ICCD Speckle Observations of Binary Stars. XVI. Measurements During 1982-1989 from the Perkins 1.8-M Telescope.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.1623F&db_key=AST
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ICCD Speckle Observations of Binary Stars.XV.An Investigation of Lunar Occultation Systems
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....112.2260M&db_key=AST
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ICCD Speckle Observations of Binary Stars. XII. Measurements During 1984-1986 From the Perkins 1.8 M Telescope
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....111..393A&db_key=AST
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Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
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Binary star speckle measurements during 1989-1993 from the SAO 6 M and 1 M telescopes in Zelenchuk
We have continued to survey visual and interferometric binary stars withsignificant orbital motion by means of speckle method at the telescopesof the Special Astrophysical Observatory (SAO) in Zelenchuk. Here wepresent the lists of 267 speckle observations made with the 6 m and the1 m telescopes in the period May 1989-November 1993.
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Probable open clusters NGC 1750 and NGC 1758 behind the Taurus dark clouds
The area of 2.5 x 2.5 deg in the direction of the Taurus dark cloudscontaining stellar groupings NGC 1746, NGC 1750, and NGC 1758 isinvestigated in the Vilnius photometric system. Magnitudes V, colorindices, color excesses, interstellar extinctions, and distances aredetermined for 116 stars, some of which are as faint as V = 13. It isconcluded that NGC 1746 is probably not a cluster. Other two groupingsof stars, NGC 1750 and NGC 1758, if real, may be open clusters at 510and 680 pc distances. Interstellar reddenings E(B-V) of both groups are0.42 and 0.37 mag, respectively. The distance of the Taurus dark cloudsin the area is found to be 175 pc, i.e. by 45 pc larger than in otherdirections farther to the south from the galactic equator.
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Fifth fundamental catalogue. Part 2: The FK5 extension - new fundamental stars
The mean positions and proper motions for 3117 new fundamental starsessentially in the magnitude range about 4.5 to 9.5 are given in thisFK5 extension. Mean apparent visual magnitude is 7.2 and is on average2.5 magnitudes fainter then the basic FK5 which has a mean magnitude of4.7. (The basic FK5 gives the mean positions and proper motions for theclassical 1535 fundamental stars). The following are discussed: theobservational material, reduction of observations, star selection, andthe system for the FK5 extension. An explanation and description of thecatalog are given. The catalog of 3117 fundamental stars for the equinoxand epoch J2000.0 and B1950.0 is presented. The parallaxes and radialvelocities for 22 extension stars with large forecasting effects aregiven. Catalogs used in the compilation of the FK5 fundamental catalogare listed.
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The distance to the high-velocity clouds - Mass infall and galactic disk formation
The high-velocity neutral hydrogen complex C in optical (Ca K)absorption against stars at distances of 1-2 kpc has been detected,confirming a previous tentative detection and placing an upper limit onthe distance to this complex. A similar (though as yet more uncertain)limit is placed to the distance to complex A. No complex is detected inabsorption against any nearby star, effectively ruling out models inwhich the clouds are formed by supershells in the local disk. If thesedistances are representative of the bulk of the high-velocity clouds,the local mass infall rate is 6 x 10 to the -9th solar mass/sq pc/yr,which would supply the disk column density in 10 billion yr. The cloudslie above the bulk of the disk, and it is shown how they may be used tomeasure the pressure of the halo and to place an upper bound on themetagalactic UV flux.
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INHABITED SKY
