Comparative statistics and origin of triple and quadruple stars
The statistics of catalogued quadruple stars consisting of two binaries(hierarchy 2 + 2), is studied in comparison with triple stars, withrespective sample sizes of 81 and 724. Seven representative quadruplesystems are discussed in greater detail. The main conclusions are asfollows. (i) Quadruple systems of ? Lyr type with similar massesand inner periods are common, in 42 per cent of the sample the outermass ratio is above 0.5 and the inner periods differ by less than 10times. (ii) The distributions of the inner periods in triple andquadruple stars are similar and bimodal. The inner mass ratios do notcorrelate with the inner periods. (iii) The statistics of outer periodsand mass ratios in triples and quadruples are different. The medianouter mass ratio in triples is 0.39 independently of the outer period,which has a smooth distribution. In contrast, the outer periods of 25per cent quadruples concentrate in the narrow range from 10 to 100yr,the outer mass ratios of these tight quadruples are above 0.6 and theirtwo inner periods are similar to each other. (iv) The outer and innermass ratios in triple and quadruple stars are not mutually correlated.In 13 per cent of quadruples both inner mass ratios are above 0.85(double twins). (v) The inner and outer orbital angular momenta andperiods in triple and quadruple systems with inner periods above 30dshow some correlation, the ratio of outer-to-inner periods is mostlycomprised between 5 and 104. In the systems with small periodratios the directions of the orbital spins are correlated, while in thesystems with large ratios they are not. The properties of multiple starsdo not correspond to the products of dynamical decay of small clusters,hence the N-body dynamics is not the dominant process of theirformation. On the other hand, rotationally driven (cascade)fragmentation possibly followed by migration of inner and/or outerorbits to shorter periods is a promising scenario to explain the originof triple and quadruple stars.
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Contribution to the search for binaries among Am stars - VIII. New spectroscopic orbits of eight systems and statistical study of a sample of 91 Am stars
This paper is the last of a series devoted to the study of Am stars,with the monitoring of radial velocities of a sample of 91 objectsduring more than 20 yr. The purpose was to determine which stars weremembers of spectroscopic binaries (SBs) and study in detail thosesystems in order to obtain observational constraints on the origin ofthe Am phenomenon.In the first part, we present the results of a detailed study of eightAm stars (HD 32893, 60489, 109762, 111057, 113697, 204918, 219675 andBD+44° 4512) observed at the Haute-Provence and Cambridgeobservatories with CORAVEL instruments. We find that these objects aresingle-lined SBs whose orbital elements are determined for the firsttime. HD 32893 is found to be a triple spectroscopic system whose thirdbody might be detected by speckle interferometry. Physical parametersare inferred for the primaries of those SBs. We then investigate theinfluence of tidal interaction and find that it has already led to thesynchronism of the primaries and to the circularization of the orbits offour of those systems.In the second part of this paper, we present the main results of ourwhole programme and derive some statistical properties of Am stars. Wegive the recapitulating table of the orbital parameters found for theSBs of our whole sample and the list of those for which no evidence forradial velocity variations could be found during our monitoring. Ourstudy shows that at least 64 per cent of Am stars are members of SBs.This rate is significantly greater than that of normal stars. Althoughsome SBs may have been not detected, this study shows that a substantialfraction of Am stars do not belong to SBs: they are either isolatedstars or members of wide binary systems.We then present some statistical properties of the orbital parameters ofthe SBs whose primary is an Am star, on an extended sample obtained byadding 29 Am SB orbits published by other authors. The corresponding eversus logP diagram shows a cut-off between the circular and theeccentric systems at P ~ 5.6 +/- 0.5 d, which indicates a typical age of0.5 - 1 × 109 yr for the Am stars, which is inagreement with the values found in our previous detailed studies. AMonte Carlo analysis shows that the distribution of the mass functionvalues f(m) is compatible with a power-law distribution N(m) ~m-α of the masses m of the companions with α =0.3 +/- 0.2 or with a Gaussian distribution centred on 0.8 +/-0.5Msolar, which indicates that the companions of Am SBs aremostly dwarf stars of type G-K-M.
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Contribution to the search for binaries among Am stars - VII. Orbital elements of seven new spectroscopic binaries, implications on tidal effects
We present the results of a radial-velocity study of seven Am stars (HD3970, 35035, 93946, 151746, 153286, 204751 and 224002) observed at theObservatoire de Haute-Provence (OHP) and the Cambridge Observatorieswith CORAVEL instruments. We find that these systems are single-linedspectroscopic binaries whose orbital elements are determined for thefirst time. Among this sample, HD 35035 and 153286 have long periods,with P = 2.8 and 9.5yr, respectively, which is rather unusual for Amstars. Four systems have orbits with large eccentricities (with e >=0.4). Physical parameters are inferred from this study for the primariesof those systems.We then investigate the influence of tidal interaction, which hasalready led to the synchronism of the primaries and/or to thecircularization of the orbits of some systems belonging to this sample.We extend this study to the list of 33 objects studied in this series ofpapers and derive values of the critical fractional radii r = R/a forcircularization and synchronization of Am-type binaries. We find thatthe stars with r >~ 0.15 are orbiting on circular orbits and thatsynchronism is likely for all components with r >~ 0.20.
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SB9: The ninth catalogue of spectroscopic binary orbits
The Ninth Catalogue of Spectroscopic Binary Orbits(http://sb9.astro.ulb.ac.be) continues the series of compilations ofspectroscopic orbits carried out over the past 35 years by Batten andcollaborators. As of 2004 May 1st, the new Catalogue holds orbits for2386 systems. Some essential differences between this catalogue and itspredecessors are outlined and three straightforward applications arepresented: (1) completeness assessment: period distribution of SB1s andSB2s; (2) shortest periods across the H-R diagram; (3)period-eccentricity relation.
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Binary Star Orbits. II. Preliminary First Orbits for 117 Systems
Orbital elements are presented for 117 binary systems with no previousorbit calculation. For nearly all of these systems, these elements mustbe regarded as preliminary, but the ephemerides presented here should berelatively accurate over the next several decades. Further, the analysisof these systems should highlight the need for their continuedobservation by dedicated programs to improve the veracity of theseelements.
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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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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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ICCD speckle observations of binary stars. 11: Measurements during 1991-1993 from the Kitt Peak 4 M telescope
One-thousand one-hundred ninety-seven observations of 730 binary starsystems, observed by means of speckle interferometry with the 4 mtelescope on Kitt Peak, are presented. Included in these binary starsare new interferometric companions to five visual binaries. Thesemeasurements, made mostly during the period 1991 to 1993, comprise the11th installment of results stemming from our speckle program at the 4 mclass telescopes on Kitt Peak, Cerro Tololo, and Mauna Kea.
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Double Star Measurements Made at Nice
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&AS..102..643M&db_key=AST
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Photoelectric photometry of stars in the Vilnius system in Kapteyn areas SA 2, 4 and 6
Photoelectric photometry in the Vilnius system of 114 standard stars inKapteyn areas SA 2, 4, and 6 is presented with mean square errors of thearithmetic mean +/- 0.005 mag. Photometrically determined spectral typesand luminosity classes of the stars are also presented.
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ICCD speckle observations of binary stars. V - Measurements during 1988-1989 from the Kitt Peak and the Cerro Tololo 4 M telescopes
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1990AJ.....99..965M&db_key=AST
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Measurements of binary stars obtained at Pic-du-Midi and at Nice
A total of 112 visual measurements of 82 close binaries observed with 2mtelescope at Pic-du-Midi are presented. In addition, 344 measurements of163 close binaries were observed with the 74-cm and 50-cm refractors atNice. All measurements were made by a micrometer with illuminated wires.
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Miscellaneous spectroscopic notes
Results of slit-spectrograph observations are reported for approximately260 stars. The data presented range from recognition of many new Ap, Am,and other unusual stars to H-alpha observations of early-typesupergiants and Be stars. The material discussed was obtained over thepast 40 years at a number of U.S. observatories and at the DominionAstrophysical Observatory in Victoria, B.C.
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Measurements of visual double stars made at PIC DU Midi and at Nice
Fifty visual measures of 37 very close binaries observed with the 2-mtelescope at Pic du Midi are presented together with 601 measures of 245close binaries observed with the 74-cm and 50-cm refractors at Nice. Allmeasurements were made by micrometer with illuminated wires. With the2-m telescope, binaries as close as 0.07 arcsec are separated, usingmagnifying powers from 2500 to 5000.
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ICCD speckle observations of binary stars. II - Measurements during 1982-1985 from the Kitt Peak 4 M telescope
This paper represents the continuation of a systematic program of binarystar speckle interferometry initiated at the 4 m telescope on Kitt Peakin late 1975. Between 1975 and 1981, the observations were obtained witha photographic speckle camera, the data from which were reduced byoptical analog methods. In mid-1982, a new speckle camera employing anintensified charge-coupled device as the detector continued the programand necessitated the development of new digital procedures for reducingand analyzing speckle data. The camera and the data-processingtechniques are described herein. This paper presents 2780 newmeasurements of 1012 binary and multiple star systems, including thefirst direct resolution of 64 systems, for the interval 1982 through1985.
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Micrometer Measures of Double Stars at Lick Observatory
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1984PASP...96..174C&db_key=AST
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Speckle interferometric measurements of binary stars. IX
Four hundred-forty measurements of 232 binary stars observed during 1981by means of speckle interferometry with the 4-m telescope at KPNO arerepresented. Newly resolved systems include Xi-1 Cet, Rho Her A, HD187321, and 59 Cyg A.
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Speckle interferometric measurements of binary stars. VIII
Six hundred measurements of 331 binary stars observed during 1980 bymeans of speckle interferometry with the 4 m telescope at Kitt PeakNational Observatory are presented. Thirty-two systems are directlyresolved for the first time. Newly resolved spectroscopic binariesinclude HR 2001, 53 Dam, HR 6388, HR 6469, 31 Omicron-2 Cyg, HR 7922,and alpha Equ.
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Speckle interferometric measurements of binary stars. VII
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1982ApJS...49..267M&db_key=AST
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Mesures d'etoiles doubles faites a Nice.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...33..275M&db_key=AST
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Mesures d'etoiles doubles a Meudon (3eme et derniere serie).
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&AS...23..205M&db_key=AST
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Measurements of double stars made at Nice
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&AS...20..391C&db_key=AST
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Photographic magnitudes of stars brighter than 7m.75 between +75° and +80° declination (Errata: 11 270)
Not Available
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Yerkes actinometry. Zone +73deg to +90deg.
Not Available
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INHABITED SKY
