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Parameters of the components of visually close binary systems: Hip 11352
Model atmospheres of the components of the visually close binary systemHip 11352 were constructed using a grid of Kurucz's blanketed models.The entire observational spectral energy distribution of the system wasused as a reference for the comparison with synthetic ones created fromthe model atmospheres. The parameters of the components of the systemwere derived as {T_eff{a} =5650±50} K,{T_eff{b} =5550±50} K, {log g_a=4.47±0.13},{log g_b=4.49±0.13}, {R_a=0.92±0.03} Rȯ,{R_b=0.88±0.02} Rȯ, {M_a=0.93±0.05Mȯ}, { M_b=0.89±0.05 Mȯ}, with aspectral type G7 for the primary and G9 for the secondary. The syntheticmagnitudes and of both components were calculated using Johnson-Cousins,Strömgren, and Tycho photometrical systems. Finally the formationand evolution of the system was discussed.
| Synthetic photometry of speckle interferometric binaries
The synthetic magnitudes and color indices of 46 speckle interferometricstars have been computed depending on their observational spectralenergy distributions. The Strömgren vby and Tycho BV passbands havebeen used to calculate magnitudes of the systems. These data whencombined with the magnitude differences of the sub-components fromspeckle interferometry observations will allow the finding of theparameters of the individual components. These parameters will improveour knowledge about binary system formation and evolution.
| Speckle interferometry of nearby multiple stars. IV. Measurements in 2004 and new orbits
The results of speckle interferometric observations of 104 binary and 6triple stars performed at the BTA 6 m telescope in 2004 October arepresented. Nearby low-mass stars are mostly observed for the program,among which 59 there are new binaries recently discovered by theHipparcos astrometric satellite. Concurrently with thediffraction-limited position measurements we obtained 154 brightnessratio measurements of binary and multiple star components in differentbands of the visible spectrum. New, first-resolved binaries are thesymbiotic star CH Cyg with a weak companion at 0.043″ separationand the pair of red dwarfs, GJ 913 = HIP 118212. In addition, we derivedthe orbital parameters for two interferometric systems: the CN-giantpair HD 210211 = HIP 109281 (P = 10.7 yr) and the G2V-K2V G2V-K2V binaryGJ 9830 = HIP 116259 (P = 15.7 yr).
| Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| Differential Radial Velocities and Stellar Parameters of Nearby Young Stars
Radial velocity searches for substellar-mass companions have focusedprimarily on stars older than 1 Gyr. Increased levels of stellaractivity in young stars hinders the detection of solar system analogs,and therefore until recently there has been a prejudice againstinclusion of young stars in radial velocity surveys. Adaptive opticssurveys of young stars have given us insight into the multiplicity ofyoung stars, but only for massive, distant companions. Understanding thelimit of the radial velocity technique, restricted to high-mass,close-orbiting planets and brown dwarfs, we began a survey of youngstars of various ages. While the number of stars needed to carry outfull analysis of the problems of planetary and brown dwarf populationand evolution is large, the beginning of such a sample is included here.We report on 61 young stars ranging in age from the β Pictorisassociation (~12 Myr) to the Ursa Major association (~300 Myr). Thisinitial search resulted in no stars showing evidence of companionslarger than ~1MJup-2MJup in short-period orbits atthe 3 σ level. We also present derived stellar parameters, as mosthave unpublished values. The chemical homogeneity of a cluster, andpresumably of an association, may help to constrain true membership, sowe present [Fe/H] abundances for the stars in our sample.
| Orbits of new Hipparcos binaries. II
We continue the presentation of new orbits for Hipparcos binariesdetermined from regular speckle interferometric observations. Most ofthe data were collected in the period between 1998.77 and 2004.82 usingthe 6 m BTA telescopeof the Special Astrophysical Observatory in Zelenchuk. New orbits arepresented for six pairs: HIP 4809, HIP 4849,HIP 5531, HIP 19206, HIP 105947, andHIP 114922. One of the pairs, HIP 114922, has M dwarfcomponents orbiting with a period of 19.72 yr. Two binaries,HIP 4809 and HIP 5531, have luminosity class IVcomponents. The periods of the orbits range from 7.30 yr to 28.99 yr.All of the orbits can be considered definitive; however, the total masserror for the systems remains high, mainly due to Hipparcos parallaxerror.
| Speckle interferometry of nearby multiple stars. III.
Not Available
| Orbits of new Hipparcos binaries. I
We present first orbits for 6 new Hipparcos binaries. The orbits weredetermined from speckle interferometric measurements collected mainly atthe6m BTAtelescope of the Special Astrophysical Observatory inZelenchuk. Three of the systems, HIP 11352, HIP 14075 andHIP 14230, have late G- or early K-type components, whileHIP 14669 = GJ 125, HIP 106972 = GJ 4210 andHIP 111685 = GJ 4287 have M-type components. The periodsof the orbits are in the range of6-28years. Mass sums and their errorsare derived for the systems. The Hipparcos parallax error is thedominating error source of themass determination.Based on observations made with the 6-m BTA telescope, which is operatedby the Special Astrophysical Observatory, Russia.
| Preliminary Orbital Elements of Four Interferometric Binary Stars
We present preliminary orbital elements for the four interferometricbinary star systems WDS 01017+2518, 02262+3428, 02442-2530, and11268-5310. For all stars these are the first orbits that have beenpublished. The data are accompanied by uncertainty estimates, residuals,and ephemerides, as well as dynamical parallaxes and individual starmasses. In all four cases regular observations within the coming yearsare encouraged to test the orbital solutions.
| Differential photometry of speckle-interferometric binary and multiple stars
A method for differential photometry of speckle-interferometric binaryand multiple stars is presented. Both the accuracy and sources ofsystematic errors of the method are analysed. The photometric accuracyranges between 0.02 m and 0.20 m, depending on the atmospheric seeing,the brightness and the separation of the system components. A comparisonbetween our magnitude differences and those of other authors ispresented.
| Speckle interferometry of nearby multiple stars. II.
This paper is a continuation of diffraction-limited speckleinterferometry of binary and multiple stars carried out at the 6-mtelescope of the Special Astrophysical Observatory in Zelenchuk. Theprogram has concentrated on nearby (π>10 mas) close binariesdiscovered or measured during the Hipparcos mission. Here, we present132 measurements of relative positions and magnitude differences for 99pairs and 8 measurements for 6 triple systems. 54 entries in the paperare new Hipparcos binaries. New triple systems with late-type dwarfcomponents, discovered in the course of observations, are HIP 8533 andHIP 25354.Based on data collected at the Special Astrophysical Observatory,Russia.{Tables 1-3 are 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?/A+A/422/627
| The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of 14 000 F and G dwarfs
We present and discuss new determinations of metallicity, rotation, age,kinematics, and Galactic orbits for a complete, magnitude-limited, andkinematically unbiased sample of 16 682 nearby F and G dwarf stars. Our63 000 new, accurate radial-velocity observations for nearly 13 500stars allow identification of most of the binary stars in the sampleand, together with published uvbyβ photometry, Hipparcosparallaxes, Tycho-2 proper motions, and a few earlier radial velocities,complete the kinematic information for 14 139 stars. These high-qualityvelocity data are supplemented by effective temperatures andmetallicities newly derived from recent and/or revised calibrations. Theremaining stars either lack Hipparcos data or have fast rotation. Amajor effort has been devoted to the determination of new isochrone agesfor all stars for which this is possible. Particular attention has beengiven to a realistic treatment of statistical biases and errorestimates, as standard techniques tend to underestimate these effectsand introduce spurious features in the age distributions. Our ages agreewell with those by Edvardsson et al. (\cite{edv93}), despite severalastrophysical and computational improvements since then. We demonstrate,however, how strong observational and theoretical biases cause thedistribution of the observed ages to be very different from that of thetrue age distribution of the sample. Among the many basic relations ofthe Galactic disk that can be reinvestigated from the data presentedhere, we revisit the metallicity distribution of the G dwarfs and theage-metallicity, age-velocity, and metallicity-velocity relations of theSolar neighbourhood. Our first results confirm the lack of metal-poor Gdwarfs relative to closed-box model predictions (the ``G dwarfproblem''), the existence of radial metallicity gradients in the disk,the small change in mean metallicity of the thin disk since itsformation and the substantial scatter in metallicity at all ages, andthe continuing kinematic heating of the thin disk with an efficiencyconsistent with that expected for a combination of spiral arms and giantmolecular clouds. Distinct features in the distribution of the Vcomponent of the space motion are extended in age and metallicity,corresponding to the effects of stochastic spiral waves rather thanclassical moving groups, and may complicate the identification ofthick-disk stars from kinematic criteria. More advanced analyses of thisrich material will require careful simulations of the selection criteriafor the sample and the distribution of observational errors.Based on observations made with the Danish 1.5-m telescope at ESO, LaSilla, Chile, and with the Swiss 1-m telescope at Observatoire deHaute-Provence, France.Complete Tables 1 and 2 are 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/418/989
| Speckle Observations of Binary Stars with the WIYN Telescope. IV. Differential Photometry
Five hundred seventy-six magnitude difference measures are presented for260 binary stars. These measures are derived from CCD-based speckleobservations taken at the WIYN 3.5 m telescope at Kitt Peak NationalObservatory during the period 1997-2000. Separations of the systemsrange from over 1" down to near the diffraction limit of the telescope.A study of multiple measures of the same targets indicates that themeasures have a typical uncertainty of better than 0.13 mag per 2 minuteobservation, and that multiple observations can be averaged to arrive atsmaller uncertainties. Results presented here are also compared, insofaras it is possible, with measures in the Hipparcos Catalogue and toprevious studies using adaptive optics. No major systematic errors wereidentified.The WIYN Observatory is a joint facility of the University ofWisconsin-Madison, Indiana University, Yale University, and the NationalOptical Astronomy Observatory.
| Speckle Observations of Binary Stars with the WIYN Telescope. II. Relative Astrometry Measures during 1998-2000
Five hundred twelve relative astrometry measures are presented for 253double stars, including 53 double stars discovered by Hipparcos. In 15cases, relative astrometry is reported for the first time for newlyconfirmed pairs. In addition, 20 high-quality nondetections ofcompanions are reported for stars suspected of being nonsingle byHipparcos. Observations were taken using a fast-readout CCD camerasystem at the WIYN 3.5 m telescope at Kitt Peak, Arizona. In comparingthese measures with ephemeris predictions for binary stars with verywell known orbits, we find that the measurement precision is better than3 mas in separation and 1° in position angle per individualobservation. Measurement precision and detection capabilities are fullydiscussed, and confirmed orbital motion is reported in four cases of theHipparcos double star discoveries. The WIYN Observatory is a jointfacility of the University of Wisconsin-Madison, Indiana University,Yale University, and the National Optical Astronomy Observatory.
| Speckle interferometry of nearby multiple stars
We present the results of diffraction-limited optical speckleinterferometry and infrared bispectrum speckle interferometry of 111double and 10 triple systems performed in 1998-1999 with the 6-mtelescope of the Special Astrophysical Observatory in Zelenchuk. Theobservations concentrated on nearby close binaries discovered during theHipparcos mission. Many nearby fast-orbiting low-mass binaries knownbefore Hipparcos were also included in the program. New companions werefirst resolved in 4 systems: HIP 5245, ADS 3179, Kui 99, and ADS 16138.In addition to accurate relative positions, magnitude differences weremeasured for most of the pairs. We combined our results with theHipparcos parallaxes to derive absolute magnitudes and spectral typesfor 63 binaries and 4 triples. Preliminary orbital elements and themass-sum are derived for HIP 689, and improved orbits are presented forHIP 16602 (CHR 117) and HIP 21280 (CHR 17). Based on data collected atthe Special Astrophysical Observatory, Russia Table 1 is only, and Table2 also, available in electronic form at the CDS via anonymons ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/385/87
| Late-type members of young stellar kinematic groups - I. Single stars
This is the first paper of a series aimed at studying the properties oflate-type members of young stellar kinematic groups. We concentrate ourstudy on classical young moving groups such as the Local Association(Pleiades moving group, 20-150Myr), IC 2391 supercluster (35Myr), UrsaMajor group (Sirius supercluster, 300Myr), and Hyades supercluster(600Myr), as well as on recently identified groups such as the Castormoving group (200Myr). In this paper we compile a preliminary list ofsingle late-type possible members of some of these young stellarkinematic groups. Stars are selected from previously established membersof stellar kinematic groups based on photometric and kinematicproperties as well as from candidates based on other criteria such astheir level of chromospheric activity, rotation rate and lithiumabundance. Precise measurements of proper motions and parallaxes takenfrom the Hipparcos Catalogue, as well as from the Tycho-2 Catalogue, andpublished radial velocity measurements are used to calculate theGalactic space motions (U, V, W) and to apply Eggen's kinematic criteriain order to determine the membership of the selected stars to thedifferent groups. Additional criteria using age-dating methods forlate-type stars will be applied in forthcoming papers of this series. Afurther study of the list of stars compiled here could lead to a betterunderstanding of the chromospheric activity and their age evolution, aswell as of the star formation history in the solar neighbourhood. Inaddition, these stars are also potential search targets for directimaging detection of substellar companions.
| The Vienna-KPNO search for Doppler-imaging candidate stars. I. A catalog of stellar-activity indicators for 1058 late-type Hipparcos stars
We present the results from a spectroscopic Ca ii H&K survey of 1058late-type stars selected from a color-limited subsample of the Hipparcoscatalog. Out of these 1058 stars, 371 stars were found to showsignificant H&K emission, most of them previously unknown; 23% withstrong emission, 36% with moderate emission, and 41% with weak emission.These spectra are used to determine absolute H&K emission-linefluxes, radial velocities, and equivalent widths of theluminosity-sensitive Sr ii line at 4077 Ä. Red-wavelengthspectroscopic and Strömgren y photometric follow-up observations ofthe 371 stars with H&K emission are used to additionally determinethe absolute Hα -core flux, the lithium abundance from the Li i6708 Å equivalent width, the rotational velocity vsin i, theradial velocity, and the light variations and its periodicity. Thelatter is interpreted as the stellar rotation period due to aninhomogeneous surface brightness distribution. 156 stars were found withphotometric periods between 0.29 and 64 days, 11 additional systemsshowed quasi-periodic variations possibly in excess of ~50 days. Further54 stars had variations but no unique period was found, and four starswere essentially constant. Altogether, 170 new variable stars werediscovered. Additionally, we found 17 new SB1 (plus 16 new candidates)and 19 new SB2 systems, as well as one definite and two possible new SB3systems. Finally, we present a list of 21 stars that we think are mostsuitable candidates for a detailed study with the Doppler-imagingtechnique. Tables A1--A3 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Speckle Observations of Binary Stars with the WIYN Telescope. I. Measures During 1997
Two hundred seventy-seven position angle and separation measures of 154double stars are presented. Three of the systems were previously unknownto be double, and 16 other systems were discovered earlier this decadeby the Hipparcos satellite. Measures are derived from speckleobservations taken with the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 mtelescope located at Kitt Peak, Arizona. Speckle images were obtainedusing two different imaging detectors, namely, a multianode microchannelarray (MAMA) detector and a fast-readout CCD. A measurement precisionstudy was performed on a sample of binaries with extremely well knownorbits by comparing the measures obtained here to the ephemerispredictions. For the CCD, the root mean square (rms) deviation ofresiduals was found to be 3.5 milliarcseconds (mas) in separation and1.2d in position angle, while the residuals of the MAMA data varieddepending on the magnification used and seeing conditions but can becomparable or superior to the CCD values. In addition, the two cameraswere compared in terms of the detection limit in total magnitude andmagnitude difference of the systems under study. The MAMA system has theability to detect some systems with magnitude differences larger than3.5, although reliable astrometry could not be obtained on theseobjects. Reliable astrometry was obtained on a system of magnitudedifference of 5.3 with the CCD system.
| Stars with large proper motions in the Astrographic zones + 32° and 33° (List II)
Not Available
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| Takýmyýldýz: | Ucgen |
| Sað Açýklýk: | 02h26m09.59s |
| Yükselim: | +34°28'10.0" |
| Görünürdeki Parlaklýk: | 8.027 |
| Uzaklýk: | 43.122 parsek |
| özdevim Sað Açýklýk: | 115.4 |
| özdevim Yükselim: | -49.9 |
| B-T magnitude: | 8.917 |
| V-T magnitude: | 8.101 |
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