Elemental abundances in the atmosphere of clump giants
Aims.The aim of this paper is to provide the fundamental parameters andabundances for a large sample of local clump giants with a highaccuracy. This study is a part of a big project, in which the verticaldistribution of the stars in the Galactic disc and the chemical anddynamical evolution of the Galaxy are being investigated. Methods:.The selection of clump stars for the sample group was made applying acolour-absolute magnitude window to nearby Hipparcos stars. Theeffective temperatures were estimated by the line depth ratio method.The surface gravities (log {g}) were determined by two methods (thefirst one was the method based on the ionization balance of iron and thesecond one was the method based on fitting of the wings of the Ca I6162.17 Å line). The abundances of carbon and nitrogen wereobtained from the molecular synthetic spectrum, and the Mg and Naabundances were derived using the non-LTE approximation. The "classical"models of stellar evolution without atomic diffusion androtation-induced mixing were employed. Results: .The atmosphericparameters ({T_eff}, log {g}, [Fe/H], {Vt}) and Li, C, N, O,Na, Mg, Si, Ca, and Ni abundances in 177 clump giants of the Galacticdisc were determined. The underabundance of carbon, overabundance ofnitrogen, and "normal" abundance of oxygen were detected. A small sodiumoverabundance was found. A possibility of a selection of the clumpgiants based on their chemical composition and the evolutionary trackswas explored. Conclusions: .The theoretical predictions based onthe classical stellar evolution models are in good agreement with theobserved surface variations of the carbon and nitrogen just after thefirst dredge-up episode. The giants show the same behaviour of thedependencies of O, Mg, Ca, and Si (α-elements) and Ni (iron-peakelement) abundances vs. [Fe/H] as dwarfs do. This allows us to use suchabundance ratios to study the chemical and dynamical evolution of theGalaxy.
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Adaptive Optics Photometry and Astrometry of Binary Stars
We present astrometric and photometric measurements of 39 binary starsmade with the adaptive optics system on the 3.6 m AdvancedElectro-Optical System (AEOS) telescope, taken from 2002 November to2003 March. The binaries have separations ranging from 0.08" to 5.11"and differential magnitudes ranging from 0.096 to 7.9. Also, we includea list of observations of 23 known binaries that we were unable toresolve. In the process of these measurements, we discovered three newcompanions to two previously known binary stars. We also discuss theeffects of scintillation and anisoplanatism on measurements of binarystar photometry in adaptive optics images. Suggestions on how tominimize these effects are then given.Based on observations made at the Maui Space Surveillance Systemoperated by Detachment 15 of the US Air Force Research Laboratory'sDirected Energy Directorate.
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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}
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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.
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Kinematics of Hipparcos Visual Binaries. II. Stars with Ground-Based Orbital Solutions
This paper continues kinematical investigations of the Hipparcos visualbinaries with known orbits. A sample, consisting of 804 binary systemswith orbital elements determined from ground-based observations, isselected. The mean relative error of their parallaxes is about 12% andthe mean relative error of proper motions is about 4%. However, even 41%of the sample stars lack radial velocity measurements. The computedGalactic velocity components and other kinematical parameters are usedto divide the stars with known radial velocities into kinematical agegroups. The majority (92%) of binaries from the sample are thin diskstars, 7.6% have thick disk kinematics and only two binaries have halokinematics. Among them, the long-period variable Mira Ceti has a verydiscordant {Hipparcos} and ground-based parallax values. From the wholesample, 60 stars are ascribed to the thick disk and halo population.There is an urgent need to increase the number of the identified halobinaries with known orbits and substantially improve the situation withradial velocity data for stars with known orbits.
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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.
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Speckle Interferometry of New and Problem Hipparcos Binaries. II. Observations Obtained in 1998-1999 from McDonald Observatory
The Hipparcos satellite made measurements of over 9734 known doublestars, 3406 new double stars, and 11,687 unresolved but possible doublestars. The high angular resolution afforded by speckle interferometrymakes it an efficient means to confirm these systems from the ground,which were first discovered from space. Because of its coverage of adifferent region of angular separation-magnitude difference(ρ-Δm) space, speckle interferometry also holds promise toascertain the duplicity of the unresolved Hipparcos ``problem'' stars.Presented are observations of 116 new Hipparcos double stars and 469Hipparcos ``problem stars,'' as well as 238 measures of other doublestars and 246 other high-quality nondetections. Included in these areobservations of double stars listed in the Tycho-2 Catalogue andpossible grid stars for the Space Interferometry Mission.
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Doppler imaging of stellar surface structure. XVI. A time-series analysis of the moderately-rotating K1-giant sigma Geminorum
We present a simultaneous photometric and spectroscopic imaging analysisof the long-period RS CVn binary sigma Gem, covering 3.6 consecutiverotation cycles with high time resolution. From six overlapping butconsecutive Doppler maps we trace the evolution of individual spotsthroughout the time range covered. All spots group either along a bandat approximately +45 degrees latitude and a width of 30 degrees, orappear centered at the equator. No polar spot is detected. We did notfind a conclusive migration pattern from the cross-correlation maps fromone rotation to the next and attribute this to a masking effect ofshort-term spot changes.
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ICCD Speckle Observations of Binary Stars. XXIII. Measurements during 1982-1997 from Six Telescopes, with 14 New Orbits
We present 2017 observations of 1286 binary stars, observed by means ofspeckle interferometry using six telescopes over a 15 year period from1982 April to 1997 June. These measurements constitute the 23dinstallment in CHARA's speckle program at 2 to 4 m class telescopes andinclude the second major collection of measurements from the MountWilson 100 inch (2.5 m) Hooker Telescope. Orbital elements are alsopresented for 14 systems, seven of which have had no previouslypublished orbital analyses.
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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.
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Starspot photometry with robotic telescopes. UBV(RI)_C and by light curves of 47 active stars in 1996/97
We present continuous multicolor photometry for 47 stars from October1996 through June 1997. Altogether, 7073 V(RI)_c, UBV, and by datapoints, each the average of three individual readings, were acquiredwith three automatic photoelectric telescopes (APTs) at FairbornObservatory in southern Arizona. Most of our targets arechromospherically active single and binary stars of spectral type G to Kbut there are also four pre-main-sequence objects and three pulsatingstars in our sample. The light variability is generally due torotational modulation of an asymmetrically spotted stellar surface andtherefore precise rotational periods and their seasonal variations aredetermined from Fourier analysis. We also report on photometricvariations of gamma CrB (A0V) with a period of 0.44534 days. All dataare available in numerical form. All data are available from CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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ICCD Speckle Observations of Binary Stars. XVII. Measurements During 1993-1995 From the Mount Wilson 2.5-M Telescope.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.1639H&db_key=AST
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ICCD Speckle Observations of Binary Stars. XVI. Measurements During 1982-1989 from the Perkins 1.8-M Telescope.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.1623F&db_key=AST
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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.
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Mesures d'etoiles doubles faites a Nice, etoiles doubles nouvelles (24eme serie) decouvertes a Nice.
Table 1 gives 1182 measurements of 682 binaries observed with the 74 and50 cm refractors. Table 2 lists 26 new binaries discovered with the 50cm refractor.
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Binary star speckle measurements during 1989-1993 from the SAO 6 M and 1 M telescopes in Zelenchuk
We have continued to survey visual and interferometric binary stars withsignificant orbital motion by means of speckle method at the telescopesof the Special Astrophysical Observatory (SAO) in Zelenchuk. Here wepresent the lists of 267 speckle observations made with the 6 m and the1 m telescopes in the period May 1989-November 1993.
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All-sky Stromgren photometry of speckle binary stars
All-sky Stromgren photometric observations were obtained for 303 specklebinaries. Most stars were in the range of V = 5-8. These data, whencombined with ratios of intensities from the CHARA speckle photometryprogram, will allow the determination of photometric indices for theindividual components of binary stars with separations as small as 0.05arcsec. These photometric indices will complement the stellar massesfrom the speckle interferometry observations to provide a much improvedmass-luminosity relationship.
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Television speckle interferometry of binary stars at the Zeiss-1000 telescope.
Not Available
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Velocity dispersions and mean abundances for Roman's G5-K1 spectroscopic groups
The velocity dispersions and U-V distributions of Roman's (1950, 1952)four spectroscopic groups (weak CN, weak line, strong line, and 4150)are compared with those of groups based only on Fe/H ratio. It is shownthat the velocity-dispersion gradient for the Roman spectroscopic groupsis greater than for the comparison group for all three velocitycomponents and for the mean orbital eccentricity, with a clearly definedminimum for the strong-line stars and a sharp upturn for the 4150 stars.The results suggest that the Roman's assignment to distinctspectroscopic groups results in more homogeneous groups than the binningon the basis of metallicity.
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A critical appraisal of published values of (Fe/H) for K II-IV stars
'Primary' (Fe/H) averages are presented for 373 evolved K stars ofluminosity classes II-IV and (Fe/H) values beween -0.9 and +0.21 dex.The data define a 'consensus' zero point with a precision of + or -0.018 dex and have rms errors per datum which are typically 0.08-0.16dex. The primary data base makes recalibration possible for the large(Fe/H) catalogs of Hansen and Kjaergaard (1971) and Brown et al. (1989).A set of (Fe/H) standard stars and a new DDO calibration are given whichhave rms of 0.07 dex or less for the standard star data. For normal Kgiants, CN-based values of (Fe/H) turn out to be more precise than manyhigh-dispersion results. Some zero-point errors in the latter are alsofound and new examples of continuum-placement problems appear. Thushigh-dispersion results are not invariably superior to photometricmetallicities. A review of high-dispersion and related work onsupermetallicity in K III-IV star is also given.
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A first catalogue of speckle-interferometric measurements of binary stars made with 6-m telescope of the USSR AS.
Not Available
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ICCD speckle observations of binary stars. V - Measurements during 1988-1989 from the Kitt Peak and the Cerro Tololo 4 M telescopes
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1990AJ.....99..965M&db_key=AST
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Third preliminary catalogue of stars observed with the photoelectric astrolabe of the Beijing Astronomical Observatory.
Not Available
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Photometric variability in chromospherically active stars. III - The binary stars
Differential UBV photometry of 49 late-type chromospherically activebinary stars has been obtained. A total of 12,353 differential UBVmagnitudes have been acquired and are used to determine seasonalphotometric periods, amplitudes, mean brightnesses, maximum spotamplitudes, 'unspotted' differential magnitudes, and times of minimumlight. Standard Fourier techniques are used to investigate the cause ofthe light variability. Eight stars are found which exhibit lightvariations due not to spot activity but rather to ellipticity and/orreflection effect. Others show combinations of all three effects. Someof the systems also show substantial differences between theirrotational and orbital period.
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Binary star orbits from speckle interferometry. II - Combined visual-speckle orbits of 28 close systems
New combined speckle/visual orbital elements are presented for 28 closebinary systems with periods ranging from 2.7 to 213 yr and semimajoraxes from 0.06 to 0.81 arcsec. New orbital results are presented for ADS1105 = STF 115 AB, ADS 1473 = Ho 311, and ADS 14121 = Wck Aa, and theelements of a number of other systems have undergone major revisions.All orbits are equinox 200, and ephemeris tables based on these orbitsprovide predictions of separations and position angles for the next 5 to40 yr, depending on the derived period. The orbit calculation method andthe weighting scheme for the observations are discussed in detail.
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ICCD speckle observations of binary stars. IV - Measurements during 1986-1988 from the Kitt Peak 4 M telescope
One thousand five hundred and fifty measurements of 1006 binary starsystems observed mostly during 1986 through mid-1988 by means of speckleinterferometry with the KPNO 4-m telescope are presented. Twenty-onesystems are directly resolved for the first time, including newcomponents to the cool supergiant Alpha Her A and the Pleiades shellstar Pleione. A continuing survey of The Bright Star Catalogue yieldedeight new binaries from 293 bright stars observed. Corrections tospeckle measures from the GSU/CHARA ICCD speckle camera previouslypublished are presented and discussed.
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Interferometric Observations of Double Stars in 1985 and 1986
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1988A&AS...72..563T&db_key=AST
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Binary Star Measurements with a Digital Speckle Interferometer of the 6-M Telescope
Not Available
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ICCD speckle observations of binary stars. II - Measurements during 1982-1985 from the Kitt Peak 4 M telescope
This paper represents the continuation of a systematic program of binarystar speckle interferometry initiated at the 4 m telescope on Kitt Peakin late 1975. Between 1975 and 1981, the observations were obtained witha photographic speckle camera, the data from which were reduced byoptical analog methods. In mid-1982, a new speckle camera employing anintensified charge-coupled device as the detector continued the programand necessitated the development of new digital procedures for reducingand analyzing speckle data. The camera and the data-processingtechniques are described herein. This paper presents 2780 newmeasurements of 1012 binary and multiple star systems, including thefirst direct resolution of 64 systems, for the interval 1982 through1985.
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Measurements of visual double stars made at PIC DU Midi and at Nice
Fifty visual measures of 37 very close binaries observed with the 2-mtelescope at Pic du Midi are presented together with 601 measures of 245close binaries observed with the 74-cm and 50-cm refractors at Nice. Allmeasurements were made by micrometer with illuminated wires. With the2-m telescope, binaries as close as 0.07 arcsec are separated, usingmagnifying powers from 2500 to 5000.
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INHABITED SKY
