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Публикации по объекту
Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters
The availability of the Hipparcos Catalogue has triggered many kinematicand dynamical studies of the solar neighbourhood. Nevertheless, thosestudies generally lacked the third component of the space velocities,i.e., the radial velocities. This work presents the kinematic analysisof 5952 K and 739 M giants in the solar neighbourhood which includes forthe first time radial velocity data from a large survey performed withthe CORAVEL spectrovelocimeter. It also uses proper motions from theTycho-2 catalogue, which are expected to be more accurate than theHipparcos ones. An important by-product of this study is the observedfraction of only 5.7% of spectroscopic binaries among M giants ascompared to 13.7% for K giants. After excluding the binaries for whichno center-of-mass velocity could be estimated, 5311 K and 719 M giantsremain in the final sample. The UV-plane constructed from these datafor the stars with precise parallaxes (σπ/π≤20%) reveals a rich small-scale structure, with several clumpscorresponding to the Hercules stream, the Sirius moving group, and theHyades and Pleiades superclusters. A maximum-likelihood method, based ona Bayesian approach, has been applied to the data, in order to make fulluse of all the available stars (not only those with precise parallaxes)and to derive the kinematic properties of these subgroups. Isochrones inthe Hertzsprung-Russell diagram reveal a very wide range of ages forstars belonging to these groups. These groups are most probably relatedto the dynamical perturbation by transient spiral waves (as recentlymodelled by De Simone et al. \cite{Simone2004}) rather than to clusterremnants. A possible explanation for the presence of younggroup/clusters in the same area of the UV-plane is that they have beenput there by the spiral wave associated with their formation, while thekinematics of the older stars of our sample has also been disturbed bythe same wave. The emerging picture is thus one of dynamical streamspervading the solar neighbourhood and travelling in the Galaxy withsimilar space velocities. The term dynamical stream is more appropriatethan the traditional term supercluster since it involves stars ofdifferent ages, not born at the same place nor at the same time. Theposition of those streams in the UV-plane is responsible for the vertexdeviation of 16.2o ± 5.6o for the wholesample. Our study suggests that the vertex deviation for youngerpopulations could have the same dynamical origin. The underlyingvelocity ellipsoid, extracted by the maximum-likelihood method afterremoval of the streams, is not centered on the value commonly acceptedfor the radial antisolar motion: it is centered on < U > =-2.78±1.07 km s-1. However, the full data set(including the various streams) does yield the usual value for theradial solar motion, when properly accounting for the biases inherent tothis kind of analysis (namely, < U > = -10.25±0.15 kms-1). This discrepancy clearly raises the essential questionof how to derive the solar motion in the presence of dynamicalperturbations altering the kinematics of the solar neighbourhood: doesthere exist in the solar neighbourhood a subset of stars having no netradial motion which can be used as a reference against which to measurethe solar motion?Based on observations performed at the Swiss 1m-telescope at OHP,France, and on data from the ESA Hipparcos astrometry satellite.Full Table \ref{taba1} is only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/430/165}
| Photoelectric Minima of Some Eclipsing Binary Stars
We present 18 minima times of 10 eclipsing binaries.
| SV Cam: Light Curve Parameters and Spot Activity Between February 2000 and April 2001
Results of a 2-yr photometric monitoring of SV Cam in B and V (Johnson)filters are presented. They are compared with binary star parametersderived from recent photometric and spectroscopic information from theliterature. The presence of surface spots is established. It is shownthat SV Cam showed spots of limited surface extent that lasted sim 100days during the 2000/2001 observing campaign.
| A light and period study of SV Camelopardalis
New BVR light curves and times of minimum light for the short period RSCVn system SV Cam were analysed to derive the physical parameters of thesystem and the parameters of the third body orbit. The light curvesobtained at the TÜBITAK National Observatory during two nights in2000 show considerable asymmetry and night-to-night variations. Theanalysis of the light curves is made using Djurasevic's inverse problemmethod. The Roche model with spotted areas on the hotter primarycomponent yields a good fit to observations. The extensive series ofpublished photoelectric minima times indicate that the eclipsing pairorbits around the common mass center of the triple system with a periodof 41.32 yr. Table 1 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/376/158
| Photoelectric Minima of Four RS CVn Type Binary Systems: RT And, SV Cam, WY Cnc, and Z Her
Not Available
| Photoelectric radial velocities, Paper XIII - 406 ninth-magnitude K0 stars in the Clube Selected Areas
Radial velocities are given for 406 ninth-magnitude late-type stars. Thestars are grouped in 10 small regions located on a systematic plan atGalactic latitudes of + or - 35 deg. Each star has been observed atleast twice, and the mean velocities are accurate to about less than 1km/s. Thirty spectroscopic binaries have been discovered; orbits havealready been given for 13 of them, and observations of the others arecontinuing.
| SV Cam, an eclipsing binary containing a BY Draconis variable
New photometric observations are presented of the short-period eclipsingbinary system SV Cam. These, together with published data, are analysedand it is shown that the system is composed of a G3 V primary componentslightly evolved above the main sequence and a K4 V secondary componentwhich also exhibits BY Draconis-type variability. The extensive seriesof published times of minima indicate that the eclipsing pair orbit athird component with a period of 64 yr.
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Наблюдательные данные и астрометрия
| Созвездие: | Жираф |
| Прямое восхождение: | 06h45m17.51s |
| Склонение: | +82°25'01.3" |
| Видимая звёздная величина: | 8.607 |
| Расстояние: | 584.795 парсек |
| Собственное движение RA: | 0.3 |
| Собственное движение Dec: | -6.1 |
| B-T magnitude: | 10.203 |
| V-T magnitude: | 8.739 |
Каталоги и обозначения:
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