Contenidos
Imágenes
Subir su imagen
DSS Images Other Images
Artículos relacionados
On The Dynamics Of Dust Grains In A Hierarchical Environment. II Triple Case
The star formation process usually leads to the formation ofprotoplanetary disks. Planets are thought to arise from the material ofthese disks. Amongst the stars in the solar neighbourhood, singlesystems like our own are a minority. Most stars are found in binaries orin systems of even higher multiplicity. In this paper, we extend thesimulations presented in Paper I (de la Fuente Marcos and de la FuenteMarcos, 1998a) to hierarchical triple systems. As in Paper I, we studythe stage of planetary formation during which the particulate materialis still dispersed as centimetre-to-metre sized primordial aggregates.We investigate the response of the particles, in a protoplanetary diskwith radius RD = 100 AU around a solar-like star, to thegravitational field of bound perturbing companions in a moderately wide(300 1600 AU) orbit. As for this problem no analytic description of theorbital evolution of the particles exists, we perform numericalintegrations using a Bulirsch Stoer integrator. For this purpose, wehave carried out a series of simulations of coplanar hierarchicalconfigurations with three stars using a direct integration code thatmodels gravitational and viscous forces. The massive protoplanetary diskis around one of the components of the triple system. As in Paper I, theevolution in time of the dust sub-disk depends mainly on the nature(prograde or retrograde) of the relative revolution of the stellarcompanions, and on the temperature and mass of the circumstellar disk.The perturbation of prograde companions induces a trailing spiralstructure across the protoplanetary sub-metric dust sub-disk.Metre-sized particles are affected by strong precession. Our resultsshow that the lifetime of particles in a disk in a hierarchical triplesystem is slightly shorter relative to its valuein Paper I, although theactual value depends on the nature, prograde or retrograde, of the outercompanion. The lifetime of particles in a hierarchical triple systemincluding a prograde inner binary and a retrograde outer body is longerthan in an equivalent triple with all the companions prograde. Dustdisks in hierarchical triple systems with both companions in retrogrademotion with respect to the particles in the disk show the shortestlifetimes. Our previous calculations suggest that disk luminosities inbinary systems are several orders of magnitude higher than those forsingle stars. Circumstellar disks in triple systems may be 5 50% moreluminous depending on the relative direction of rotation.
| 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.
| Vitesse radiales dans 4 Selected Areas.
Not Available
|
Enviar un nuevo artículo
Enlaces relacionados
- - No se han encontrado enlaces -
En viar un nuevo enlace
Miembro de los siguientes grupos:
|
Datos observacionales y astrométricos
| Constelación: | Triángulo |
| Ascensión Recta: | 02h40m26.18s |
| Declinación: | +32°19'13.6" |
| Magnitud Aparente: | 7.434 |
| Distancia: | 165.837 parsecs |
| Movimiento Propio en Ascensión Recta: | 23.7 |
| Movimiento Propio en Declinación: | 0.6 |
| B-T magnitude: | 7.631 |
| V-T magnitude: | 7.451 |
Catálogos y designaciones:
|
