|Astrometric orbits of SB^9 stars|
Hipparcos Intermediate Astrometric Data (IAD) have been used to deriveastrometric orbital elements for spectroscopic binaries from the newlyreleased Ninth Catalogue of Spectroscopic Binary Orbits(SB^9). This endeavour is justified by the fact that (i) theastrometric orbital motion is often difficult to detect without theprior knowledge of the spectroscopic orbital elements, and (ii) suchknowledge was not available at the time of the construction of theHipparcos Catalogue for the spectroscopic binaries which were recentlyadded to the SB^9 catalogue. Among the 1374 binaries fromSB^9 which have an HIP entry (excluding binaries with visualcompanions, or DMSA/C in the Double and Multiple Stars Annex), 282 havedetectable orbital astrometric motion (at the 5% significance level).Among those, only 70 have astrometric orbital elements that are reliablydetermined (according to specific statistical tests), and for the firsttime for 20 systems. This represents a 8.5% increase of the number ofastrometric systems with known orbital elements (The Double and MultipleSystems Annex contains 235 of those DMSA/O systems). The detection ofthe astrometric orbital motion when the Hipparcos IAD are supplementedby the spectroscopic orbital elements is close to 100% for binaries withonly one visible component, provided that the period is in the 50-1000 drange and the parallax is >5 mas. This result is an interestingtestbed to guide the choice of algorithms and statistical tests to beused in the search for astrometric binaries during the forthcoming ESAGaia mission. Finally, orbital inclinations provided by the presentanalysis have been used to derive several astrophysical quantities. Forinstance, 29 among the 70 systems with reliable astrometric orbitalelements involve main sequence stars for which the companion mass couldbe derived. Some interesting conclusions may be drawn from this new setof stellar masses, like the enigmatic nature of the companion to theHyades F dwarf HIP 20935. This system has a mass ratio of 0.98 but thecompanion remains elusive.
|Reprocessing the Hipparcos Intermediate Astrometric Data of spectroscopic binaries. II. Systems with a giant component|
By reanalyzing the Hipparcos Intermediate Astrometric Data of a largesample of spectroscopic binaries containing a giant, we obtain a sampleof 29 systems fulfilling a carefully derived set of constraints andhence for which we can derive an accurate orbital solution. Of these,one is a double-lined spectroscopic binary and six were not listed inthe DMSA/O section of the catalogue. Using our solutions, we derive themasses of the components in these systems and statistically analyzethem. We also briefly discuss each system individually.Based on observations from the Hipparcos astrometric satellite operatedby the European Space Agency (ESA 1997) and on data collected with theSimbad database.
|The tidal effects on the lithium abundance of binary systems with giant component|
We analyse the behavior of lithium abundance as a function of effectivetemperature, projected rotational velocity, orbital period andeccentricity for a sample of 68 binary systems with giant component andorbital period ranging from about 10 to 6400 days. For these binarysystems the Li abundances show a gradual decrease with temperature,paralleling the well established result for single giants. We have alsoobserved a dependence of lithium content on rotation. Binary systemswith moderate to high rotation present also moderate to high Li content.This study shows also that synchronized binary systems with giantcomponent seem to retain more of their original lithium than theunsynchronized systems. For orbital periods lower than 100 to 250 days,typically the period of synchronization for this kind of binary systems,lithium depleted stars seems to be unusual. The suggestion is made thatthere is an ``inhibited zone" in which synchronized binary systems withgiant component having lithium abundance lower than a threshold levelshould be unusual. Based on observations collected at ESO, La Silla.
|Dating Ptolemy's star catalogue through proper motions : the Hipparchan epoch.|
|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.
|Statistical Analysis of a Sample of Spectroscopic Binaries Containing Late Type Giants|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&A...271..125B&db_key=AST
|List of Estimated Angular Separations of Spectroscopic Binaries|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1981A&AS...44...47H&db_key=AST
|Radial velocity study of four southern RS CVn candidates and related field stars|
Radial velocity variations are demonstrated for four southern RS CVncandidates: HD 39937, 101379, 155555, and 174429. The period of HD155555 appears to have decreased by about one part in 100,000 over thepast 18 yr. In addition, high-resolution observations of the Ca II H andK profiles and the Mg II 2800-A emission doublet are presented. Theseenhance the likelihood of these being RS CVn objects. Radial velocitydata for 15 other late-type bright field stars are presented. Some ofthese were observed by Copernicus and may exhibit unusual chromospheres,while the rest lack radial velocity information as tabulated in theBright Star Catalog. All velocity measures have been corrected to theIAU heliocentric system.
|Seventh catalogue of the orbital elements of spectroscopic binary systems.|
|Luminosity and velocity distributions of high-luminosity red stars. IV. The G-type giants|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974PASP...86..129E&db_key=AST
|Spectroscopic binaries with circular orbits.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971AJ.....76..544L&db_key=AST
|Results of an infrared stellar survey.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968AJ.....73..431P&db_key=AST
|The radial velocities of 60 southern stars.|