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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.
| An Apparent Descriptive Method for Judging the Synchronization of Rotation of Binary Stars
The problem of the synchronous rotation of binary stars is judged byusing a synchronous parameter Q introduced in an apparent descriptivemethod. The synchronous parameter Q is defined as the ratio of therotational period to the orbital period. The author suggests severalapparent phenomenal descriptive methods for judging the synchronizationof rotation of binary stars. The first method is applicable when theorbital inclination is well-known. The synchronous parameter is definedby using the orbital inclination i and the observable rotationalvelocity (V1,2 sin i)M. The method is mainly suitable for eclipsingbinary stars. Several others are suggested for the cases when theorbital inclination i is unknown. The synchronous parameters are definedby using a1,2 sin i,m1,2 sin3 i, the mass function f (m) andsemi-amplitudes of the velocity curve, K1,2 given in catalogue ofparameters of spectroscopic binary systems and (V1,2 sin i)M. Thesemethods are suitable for spectroscopic binary stars including those thatshow eclipses and visual binary stars concurrently. The synchronousparameters for fifty-five components in thirty binary systems arecalculated by using several methods. The numerical results are listed inTables 1 and 2. The statistical results are listed in Table 3. Inaddition, several apparent descriptive methods are discussed.
| 163. List of Minima Timings of Eclipsing Binaries by BBSAG Observers
Not Available
| 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
| 162-nd List of Minima Timings of Eclipsing Binaries by BBSAG Observers
Not Available
| Period Changes in Four Algol-Type Binaries: SX Dra, AV Del, CU Peg and DK Peg
Orbital period changes of four neglected short-period semidetachedAlgols, SX Dra, AV Del, CU Peg and DK Peg, are presented based on theanalysis of their O-C observations. It is found that the three systems,AV Del, CU Peg and DK Peg, show rapid period increase at rates of dP/dt= +3.15 × 10-6, +2.00 × 10-6 and +4.88× 10-7 days/year respectively. For the other system, SXDra, a possible periodic variation in the orbital period is discoveredto superimpose on a very rapid period increase (dP/dt = +1.09 ×10-5 days/year). The period increases of the four Algols canbe explained by a mass transfer from the secondary to the more massiveprimary, which is in agreement with the semi-detached configurations ofthese systems. However, since the period increases are rather rapid, themass transfer should be on a dynamical time scale. The cyclic periodchange in SX Dra suggests that there may exist a third body in thissystem.
| 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.
| A Search for Trojan Extrasolar Planets: Planets in V442 Cas and YZ Aql?
In this project we are exploring the light curves of eclipsing binariesfor the signature of planets that may exist at the L4 and L5 Lagrangepoints of the stellar system. While no binaries are known to exist thatstrictly satisfy the stellar mass ratio constraint for the restrictedthree-body problem, the general solution would allow a planet formed atthe L-point to remain there if there are no major perturbing bodies suchas an additional planet. We have coined such objects "Trojan planets."The advantage of this approach is that the phases of the planetaryeclipses are known. We picked systems with deep primary eclipses, tomaximize the amount of system light eclipsed by the planet when in frontof the hotter star. We also scanned the Finding List for Observers ofInteractive Binary Stars, for G dwarf systems ,but found only a few thatwere high inclination and detached. The target list includes QY Aql, YZAql, V442 Cas, SS Cet, S Cnc, VW Cyg, WW Cyg, RR Dra, RX Gem, RY Gem, VWHya, Y Leo, TV Mon, BN Sct, UW Vir, AC UMa, TX UMa, and GSC 1657. Wehave concentrated on V442 Cas and YZ Aql, based on initial results thatshow anomalies in the light curves near the phases where a Trojan planeteclipse is expected. We present results on these two, as well as initialresults for some of the other systems. We gratefully acknowledge thesupport of the National Science Foundation, through grants AST-9731062and AST-0089248. We also appreciate the support of the Fund forAstrophysical Research. Gregory Shelton and Brenda Corbin, at the U.S.naval Observatory Library, have been indispensable in providingreferences for these binary systems. This research has made use of theSimbad database, operated at CDS, Strasbourg, France
| Long-time behavior of orbital periods of some Algol-type eclipsing binaries
Orbital period variations of six semi-detached binaries, UW Cyg, RX Hya,AK Ser, AC Tau, UW Vir and VV Vul, are presented based on the analysisof their O-C observations. For AK Ser and VV Vul, their orbital periodsmay show secular increase at rates of dP/dt=+7.94 10-7 and+3.43 10-6 days/year. For UW Cyg, its orbital period isrevised, and the O-C curve shows a cyclic variation with a period of49.2 years and an amplitude of 0fd 0383. For the other three systems, RXHya, AC Tau and UW Vir, the changes in their orbital periods appear morecomplex but their O-C curves can be represented by periodic variations(with periods of 54.3, 29.8 and 45.9 years) superimposed on upwardparabolic segments. The components of upward curving parabolicvariations in RX Hya, AC Tau and UW Vir indicate secular period increasewith rates of dP/dt=+1.04 10-6, +7.11 10-7 and+1.73 10-6 days/year respectively. The secular periodincrease in the five systems, RX Hya, AK Ser, AC Tau, UW Vir and VV Vul,can be explained by mass transfer from the less to the massivecomponents, which is consistent with their semi-detached configurations.The periodic changes of the orbital periods in UW Cyg, RX Hya, AC Tau,UW Vir may be caused by the light-time effects due to the existence ofthe third bodies. Tables 2 to 7 are only available in electronic form athttp://www.edpsciences.org
| Do the physical properties of Ap binaries depend on their orbital elements?
We reveal sufficient evidence that the physical characteristics of Apstars are related to binarity. The Ap star peculiarity [represented bythe Δ(V1-G) value and magnetic field strength] diminishes witheccentricity, and it may also increase with orbital period(Porb). This pattern, however, does not hold for largeorbital periods. A striking gap that occurs in the orbital perioddistribution of Ap binaries at 160-600d might well mark a discontinuityin the above-mentioned behaviour. There is also an interestingindication that the Ap star eccentricities are relatively lower thanthose of corresponding B9-A2 normal binaries for Porb>10d.All this gives serious support to the pioneering idea of Abt &Snowden concerning a possible interplay between the magnetism of Apstars and their binarity. Nevertheless, we argue instead in favour ofanother mechanism, namely that it is binarity that affects magnetism andnot the opposite, and suggest the presence of a newmagnetohydrodynamical mechanism induced by the stellar companion andstretching to surprisingly large Porb.
| Radio star catalogue observed in San Juan (RSSJ95)
Using the data observed in San Juan with the photoelectric AstrolabeMark II of the Beijing Astronomical Observatory from February, 1992 toMarch, 1997, the radio star catalogue in San Juan(RSSJ95) has beencompiled. There are 69 radio stars in this catalogue. The positions ofthe radio stars are for the epoch of observation and the equinox J2000.0and a system close to that of the system FK5. The mean precisions are+/-2.2 ms and +/-0.035'' in right ascensions and declinations,respectively. The magnitudes of stars are from 0.9 to 10.7. Thedeclinations are from -2fdg 5 to -60(deg) . The mean epoch is 1995.1.Finally, the comparison results between the Hipparcos catalogue andRSSJ95 are given.
| San Juan radio star catalogue and comparison with HIPPARCOS catalogue.
Not Available
| Accurate Positions for Radio Stars as Determined from CCD Observations in the Extragalactic Reference Frame.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.1679S&db_key=AST
| The calculation of critical rotational periods in three typical close binary systems based on synchronization theory.
Not Available
| Measurement and study of rotation in close binary stars (III) Statistical analysis of synchronization.
Not Available
| 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.
| Radio continuum emission from stars: a catalogue update.
An updated version of my catalogue of radio stars is presented. Somestatistics and availability are discussed.
| Measurement and analysis of rotation in close binaries. II. Calculation of synchronism.
Not Available
| Measurement and Analysis of Rotation in Close Binary Stars - Part One - Observations and Results
Not Available
| An astrometric catalogue of radio stars
The first part is presented of a radio star catalog encompassing 186objects whose selection was guided by the priority criteria of theHipparchos Input Catalogue Consortium. Since these criteria are wellsuited to the need for linkage of ground-based optical systems to radioreference frames, this first selection is also considered a suitablebase for the catalog. Seventeen categories of stellar parameters arefurnished for each of the stars, including optical and radio positions,optical and radio parallax, radial velocity, type of variability, andoptical structure.
| Statistical Study of the Rotation of ALGOLS
Not Available
| A Study of the DM and SD Type Eclipsing Variables by Means of the Cluster Analysis Technique
Not Available
| Statistical investigation of chemically peculiar stars. VI. Eclipsing binaries.
Not Available
| Spectral types of 80 early-type stars of variable radial velocity
MK spectral types are given for 80 normal early-type stars of variableradial velocity. These spectral types were determined from spectrogramstaken with the Lick Observatory 0.9-m refractor during the years1957-58.
| A Catalogue of Classical Evolved Algol-Type Binary Candidate Stars
Not Available
| Synchronization in eclipsing binary stars
Improving previous studies, the synchronism between rotation andrevolution has been rediscussed for close binaries by inspection of thepublished rotational velocities of about 140 eclipsing (and ellipsoidal)binary components. Basically, it has been found that almost all membersof detached systems are synchronized up to fractional radii of rapproximately 0.15, whereas, below this r-value, both synchronized andasynchronized rotators are encountered with roughly comparable frequencyup to r approximately equal to or less than 0.10. The corresponding highfraction of synchronized stars with r less than 0.15 appears to beclearly incompatible with current theoretical predictions (e.g., Zahn,1977) on synchronization time scales.
| 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.
| New ephemerides for 120 eclipsing binary stars
Abstract image available at:http://adsabs.harvard.edu/abs/1980ApJS...44..241M
| On the surface distribution of chemical anomalies of AP stars in spectroscopic binary systems
By estimating the orbital inclinations of non-eclipsing Ap spectroscopicbinaries with periods less than 13 days, we can obtain a markedstatistical result on the frequency distribution of the inclinationswhich strongly suggests that the abundance anomalies of Ap componentstend to concentrate towards the stellar polar region. This would providea critical test for models of Ap stars
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| Takýmyýldýz: | Basakci |
| Sað Açýklýk: | 13h15m20.74s |
| Yükselim: | -17°28'16.9" |
| Görünürdeki Parlaklýk: | 9.17 |
| özdevim Sað Açýklýk: | -50.8 |
| özdevim Yükselim: | -21.4 |
| B-T magnitude: | 9.517 |
| V-T magnitude: | 9.199 |
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