Contingut
Imatges
Carregar la teva Imatge
DSS Images Other Images
Articles Relacionats
The Rotation of Binary Systems with Evolved Components
In the present study we analyze the behavior of the rotational velocity,vsini, for a large sample of 134 spectroscopic binary systems with agiant star component of luminosity class III, along the spectral regionfrom middle F to middle K. The distribution of vsini as a function ofcolor index B-V seems to follow the same behavior as their singlecounterparts, with a sudden decline around G0 III. Blueward of thisspectral type, namely, for binary systems with a giant F-type component,one sees a trend for a large spread in the rotational velocities, from afew to at least 40 km s-1. Along the G and K spectral regionsthere are a considerable number of binary systems with moderate tomoderately high rotation rates. This reflects the effects ofsynchronization between rotation and orbital motions. These rotatorshave orbital periods shorter than about 250 days and circular or nearlycircular orbits. Except for these synchronized systems, the largemajority of binary systems with a giant component of spectral type laterthan G0 III are composed of slow rotators.
| 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.
| A catalog of rotational and radial velocities for evolved stars
Rotational and radial velocities have been measured for about 2000evolved stars of luminosity classes IV, III, II and Ib covering thespectral region F, G and K. The survey was carried out with the CORAVELspectrometer. The precision for the radial velocities is better than0.30 km s-1, whereas for the rotational velocity measurementsthe uncertainties are typically 1.0 km s-1 for subgiants andgiants and 2.0 km s-1 for class II giants and Ib supergiants.These data will add constraints to studies of the rotational behaviourof evolved stars as well as solid informations concerning the presenceof external rotational brakes, tidal interactions in evolved binarysystems and on the link between rotation, chemical abundance and stellaractivity. In this paper we present the rotational velocity v sin i andthe mean radial velocity for the stars of luminosity classes IV, III andII. Based on observations collected at the Haute--Provence Observatory,Saint--Michel, France and at the European Southern Observatory, LaSilla, Chile. Table \ref{tab5} also available in electronic form at CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| The ROSAT all-sky survey catalogue of optically bright late-type giants and supergiants
We present X-ray data for all late-type (A, F, G, K, M) giants andsupergiants (luminosity classes I to III-IV) listed in the Bright StarCatalogue that have been detected in the ROSAT all-sky survey.Altogether, our catalogue contains 450 entries of X-ray emitting evolvedlate-type stars, which corresponds to an average detection rate of about11.7 percent. The selection of the sample stars, the data analysis, thecriteria for an accepted match between star and X-ray source, and thedetermination of X-ray fluxes are described. Catalogue only available atCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| 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.
| An atlas of 12 rather subtle composite spectra
True composite spectra, at MK classification dispersion, have beenobtained from the components of close visual binaries. From an availableset of 46 composites, 12 are presented in photographic montages with thespectra of their component stars for comparison. These 12, ranging inspectral type from B2 to G5, illustrate mainly the less easilyrecognized composite spectra. An analysis of their peculiaritiesgenerates seven typical clues which can alert the classifier to thecomposite nature of a spectrum under examination.
| Close visual binaries. I - MK classifications
Each component of 170 close visual binaries has been classified with newprocedures for controlling contamination problems. These classificationsare presented and are shown to be on the MK system. Two sources of areascanner UBV photometry were compared in order to establish homogeneousphotometric as well as spectroscopic data. From a consideration ofsystematic errors in the V magnitude difference (Delta V) betweencomponents the photometry of Hurly and Warner (1983) is to be preferred.Absolute magnitudes for each binary are derived from Delta V via atested MK - M(v) map.
| Close visual binaries. III - Parameters and evolutionary status
New Yale isochrones, which have been tested for accuracy by Corbally(1984), provide the means to investigate interesting visual binaries,especially those whose classifications and photometry do not match well.Various parameters are deduced for those binaries which fitted theisochrones (e.g. ages, metal abundances, luminosities of peculiarstars); various solutions are systematically developed for those whichdid not fit; and a likely status of evolution is proposed (e.g.,duplicity of the components, premain-sequence, blue straggler,horizontal branch, optical pair, data inaccuracies). Evolution aroundthe helium flash and diffusion theory are briefly considered. Theseparameters and statuses provide a wealth of new stellar data andsuggestions for further investigation.
| New Spectral Classifications on the MK System for Visual Double Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980PASP...92..493C&db_key=AST
| Measures of Visual Double Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&AS...39..197W&db_key=AST
| Visual double stars measured at Las Campanas Observatory, Chile.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975PASP...87..945H&db_key=AST
| Double star measures-3rd series
Not Available
|
Enviar un nou article
Enllaços Relacionats
- - No s'ha trobat enllaços -
Enviar un nou enllaç
Membre dels grups següents:
|
Dades d'Observació i Astrometria
| Constel·lació: | Apus |
| Ascensió Recta: | 14h53m13.70s |
| Declinació: | -73°11'24.0" |
| Magnitud Aparent: | 5.6 |
| Distancia: | 98.135 parsecs |
| Moviment propi RA: | 16.4 |
| Moviment propi Dec: | 32.4 |
| B-T magnitude: | 6.928 |
| V-T magnitude: | 5.871 |
Catàlegs i designacions:
|
