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HD 155550


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Absolute parameters of the Algol binary Z Vul
Spectra in the wavelength range 4230-9150 Å and the firstlight curves of Z Vul in the infrared J, H and K bands are presented.Our infrared JHK light curves and radial velocities, together withpublished radial velocity and UBV data are analyzed in order todetermine a new set of stellar parameters. This allows us to determinenew absolute parameters of the stellar components, the interstellarreddening and the distance to the system. We discuss the rotation of theprimary star, finding that must be rotating faster than synchronous.From the visual-infrared photometry we find no evidence of IRexcess in the system.

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.

Close binary stars in ob-association regions i. preliminary investigation
We performed a sample of O- and B-eclipsing binary stars inOB-association regions and obtained the preliminary list of 147 binariesin 45 OB-association regions. We tried to elucidate the question whether(or not) the close binaries belong to corresponding OB-associations,from the commonness of their proper motions, radial velocities anddistances. Based on the completeness of the data,the binaries aredevided into three groups and the scheme for calculation of degree ofbelonging of stars to OB-associations is developed. Necessary data arenot available for nine systems and they are given in a specific table.For 12 cases, the binaries project onto the regions of two associations.We show that 33 (22.3%) close binary stars are members, 65 (43.9%) areprobable members and 39 (26.4%) are less probable members of theOB-associations. We find that 11 binaries belong to the Galaxybackground. The comparison of the distributions of orbital periods forthe binaries in OB-associations and for O-, B-binaries of the Galaxybackground shows their considerable differences in the vicinity of thetwo-day period.

Up-to-Date Linear Elements of Eclipsing Binaries
About 1800 O-C diagrams of eclipsing binaries were analyzed and up-todate linear elements were computed. The regularly updated ephemerides(as a continuation of SAC) are available only in electronic form at theInternet address: http://www.as.ap.krakow.pl/ephem/.

Catalogue of Algol type binary stars
A catalogue of (411) Algol-type (semi-detached) binary stars ispresented in the form of five separate tables of information. Thecatalogue has developed from an earlier version by including more recentinformation and an improved layout. A sixth table lists (1872) candidateAlgols, about which fewer details are known at present. Some issuesrelating to the classification and interpretation of Algol-like binariesare also discussed.Catalogue is only available in electronic form at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/417/263

Stars with the Largest Hipparcos Photometric Amplitudes
A list of the 2027 stars that have the largest photometric amplitudes inHipparcos Photometry shows that most variable stars are all Miras. Thepercentage of variable types change as a function of amplitude. Thiscompilation should also be of value to photometrists looking forrelatively unstudied, but large amplitude stars.

Far-Ultraviolet Stellar Photometry: Fields Centered on rho Ophiuchi and the Galactic Center
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..104..101S&db_key=AST

Far-ultraviolet stellar photometry: Fields in Sagittarius and Scorpius
Far-ultraviolet photometry for 741 objects in a field in Sagittariuscentered near M8 and 541 objects in a field centered near sigma Scorpiiis presented. These data were extracted from electographic imagesobtained with two cameras during a shuttle flight in 1991 April/May. Thecameras provided band passes with lambdaeff = 1375 A andlambdaeff = 1781 A. Synthetic colors show that these bandsare sensitive to effective temperature for hot stars. Our measurementswere placed on a quantitative far-ultraviolet magnitude scale byconvolving the spectra of stars observed by IUE with our cameras'spectral response functions. Fifty-eight percent of the ultravioletobjects were identified with visible stars using the SIMBAD databasewhile another 40% of the objects are blends of early type stars tooclose together to separate with our resolution. Our photometry iscompared with that from the TD-1, OAO 2, and ANS satellites and the S201(Apollo 16) far-ultraviolet camera and found to agree at the level of afew tenths of a magnitude. Unlike previous studies, almost half of theidentified visual counterparts to the ultraviolet objects are early Bstars. A plot of distance modulus against ultraviolet color excessreveals a significant population of stars with strong ultravioletexcess.

Radio continuum emission from stars: a catalogue update.
An updated version of my catalogue of radio stars is presented. Somestatistics and availability are discussed.

UBV photometry of selected eclipsing binary stars
The study reports new UBV observations of 69 eclipsing binary stars andprovides outside-eclipse averages. Revised photometric properties offive of the binaries, for which absolute properties were publishedpreviously, are computed. Comparisons are made with previous photometry,when available, and notes are given for some individual systems.

Empirical temperature calibrations for early-type stars
Three temperature calibrations of suitable photometric quantities havebeen derived for O and B stars. A sample of 120 stars with reliableT(eff.) determinations has been used for establishing each calibration.The different calibrations have been critically discussed and compared.Temperature determinations for 1009 program stars have been obtainedwith an accuracy of the order of 10 percent.

A microwave survey of southern active stars
The results of a survey of 153 active-chromosphere stars made with theParkes 64-m telescope at 5.0/8.4 GHz from 1981 to 1987 are reported.Microwave emission was detected from 70 stars on at least one occasion,with the highest detection rate of 68 percent from the RS CVn group. TheCa II stars and Algol-type binaries yielded detection rates of 44 and 30percent, respectively. The maximum powers emitted by the stars at5.0/8.4 GHz ranged over five orders of magnitude, with a median of 2.5 x10 to the 10th W/Hz. The maximum brightness temperatures had a smallerrange of three orders of magnitude, with a median of 3.6 x 10 to the 9thK.

The period distribution of unevolved close binary systems
Period distributions have been examined for various spectral types ofabout 600 (eclipsing and spectroscopic) close binaries, which are likelyto be substantially unevolved. The comparison with the previouscorresponding analyses of extensive (but heterogeneous) binary samplesallows a clarification of the extent of the evolutionary andobservational selection effects. Remarkably, this analysis reveals agreat deficiency of short period binaries (with periods corresponding tocase A mass transfer) in the whole spectral range. For the late spectraltypes, this result may be connected with postformation angular momentumloss caused by stellar wind magnetic braking; at least for the late Band A spectral range, a ready interpretation of this finding is thatclose binaries of corresponding periods and spectral types are rarelyformed.

Catalogue of Eclipsing and Spectroscopic Binary Stars in the Regions of Open Clusters
Not Available

Statistics of categorized eclipsing binary systems Lightcurve shapes, periods, and spectral types
The statistics of the light curve morphologies, eclipse depths, orbitalperiods, and spectral types of about 1000 eclipsing binary systems areexamined, after attempting to subdivide these binaries into variousbasic evolutionary categories. The applicability of statisticalcriteria, based on light curve morphologies and eclipse depths, for thecategorization of eclipsing binaries has been found more limited thanpreviously believed. In particular, EW-type light curves turn out to begood indicators of contact systems (though not conversely), while EA-and EB-type light curves have little physical significance. Moreover,the study reveals a strong deficit of short-period noncontact systems inthe whole spectral range, together with an underabundance of early-typecontact binaries (compared with the number of late-type contact pairs).Interestingly, the distribution of evolved Algol-type systems isshifted, on average, to periods longer than those of unevolved detachedsystems in the OB and early A spectral range (and to shorter periods inthe F spectral range).

A uvby, beta photometric survey of southern hemisphere
A uvby, beta photometric study of southern hemisphere eclipsing binarystars has been undertaken at Cerro Tololo Inter-American Observatory.The standardized colors and V magnitudes for 288 binaries at quadratureand/or at minimum are presented, along with an indication of theaccuracy of the standardization and photometry. Discussions of theresolving time of the pulse-counting photometers and of the atmosphericextinction at CTIO are included.

A catalogue of parameters for eclipsing binaries
Not Available

Minima of Southern Eclipsing Variables, 1975-1979 Siding Spring
Not Available

On zero-point drift in astronomical photoelectric photometry
Not Available

Non-Lte Model Atmospheres.VI. Limb Darkening and Rotation Broadening of H&alpha
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJ...161.1129M&db_key=AST

Investigations of a Milky Way field in Scorpius. VI. Radial velocities of bright O and B stars
Not Available

Survey of Spectra of Southern Eclipsing Binaries.
Not Available

A survey of variable stars in MWF 186
Not Available

Die Bedeckungsveraenderlichen.
Not Available

Notes on eclipsing variable stars estimated on Harvard plates (Errata: 4 V)
Not Available

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Gözlemler ve gökölçümü verileri

Takýmyýldýz:Akrep
Sað Açýklýk:17h13m44.99s
Yükselim:-32°51'09.2"
Görünürdeki Parlaklýk:8.086
Uzaklýk:724.638 parsek
özdevim Sað Açýklýk:2.5
özdevim Yükselim:-0.8
B-T magnitude:8.142
V-T magnitude:8.091

Kataloglar ve belirtme:
Özgün isimleri   (Edit)
HD 1989HD 155550
TYCHO-2 2000TYC 7365-1115-1
USNO-A2.0USNO-A2 0525-27473351
HIPHIP 84282

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