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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}
| 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.
| Radial-velocity measurements. V - Ground support of the HIPPARCOS satellite observation program
The paper presents data on 1070 radial velocity measurements of starsdistributed in 39 fields measuring 4 deg x 4 deg. The PPO series ofFehrenbach et al. (1987) and Duflot et al. (1990) is continued using theFehrenbach objective prism method.
| 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.
| CA II H and K measurements made at Mount Wilson Observatory, 1966-1983
Summaries are presented of the photoelectric measurements of stellar CaII H and K line intensity made at Mount Wilson Observatory during theyears 1966-1983. These results are derived from 65,263 individualobservations of 1296 stars. For each star, for each observing season,the maximum, minimum, mean, and variation of the instrumental H and Kindex 'S' are given, as well as a measurement of the accuracy ofobservation. A total of 3110 seasonal summaries are reported. Factorswhich affect the ability to detect stellar activity variations andaccurately measure their amplitudes, such as the accuracy of the H and Kmeasurements and scattered light contamination, are discussed. Relationsare given which facilitate intercomparison of 'S' values with residualintensities derived from ordinary spectrophotometry, and for convertingmeasurements to absolute fluxes.
| Einstein Observatory magnitude-limited X-ray survey of late-type giant and supergiant stars
Results are presented of an extensive X-ray survey of 380 giant andsupergiant stars of spectral types from F to M, carried out with theEinstein Observatory. It was found that the observed F giants orsubgiants (slightly evolved stars with a mass M less than about 2 solarmasses) are X-ray emitters at the same level of main-sequence stars ofsimilar spectral type. The G giants show a range of emissions more than3 orders of magnitude wide; some single G giants exist with X-rayluminosities comparable to RS CVn systems, while some nearby large Ggiants have upper limits on the X-ray emission below typical solarvalues. The K giants have an observed X-ray emission level significantlylower than F and F giants. None of the 29 M giants were detected, exceptfor one spectroscopic binary.
| The Perkins catalog of revised MK types for the cooler stars
A catalog is presented listing the spectral types of the G, K, M, and Sstars that have been classified at the Perkins Observatory in therevised MK system. Extensive comparisons have been made to ensureconsistency between the MK spectral types of stars in the Northern andSouthern Hemispheres. Different classification spectrograms have beengradually improved in spite of some inherent limitations. In thecatalog, the full subclasses used are the following: G0, G5, G8, K0, K1,K2, K3, K4, K5, M0, M1, M2, M3, M4, M5, M6, M7, and M8. Theirregularities are the price paid for keeping the general scheme of theoriginal Henry Draper classification.
| 1988 Revised MK Spectral Standards for Stars GO and Later
Not Available
| A comparison between Washington and DDO photometry of field red giants
Washington CMT1T2 photometry of a sample of field red giants is comparedwith DDO colors obtained by McClure (1970) and Janes (1975) to determinethe relative sensitivities of the metallicity indices of the twosystems. Washington line-blanketing indices delta(M-T1) and delta(C-M)were derived, and found to correlate very well with each other, inaddition to correlating quite well with the DDO metallicity index.Furthermore, any N/A or C/A abundance variations which may exist amongthe present sample of old disk giants do not appear to significantlyeffect the delta(C-M) index. The study indicates that delta(C-M) shouldprovide a useful photometric metal abundance indicator, and is capableof providing estimates accurate to about + or - 0.2 dex over the Fe/Habundance range of +0.4 to -0.8.
| 1985 revised MK spectral standards : stars GO and later
Not Available
| A photometric search for halo binaries. I - New observatinal data. II - Results
Carney (1982) has reported JHK photometry for 76 Hyades dwarfs. Inconnection with the present investigation, results of similarobservations of field halo stars are provided along with some uvbyphotometry. In addition, older spectrophotometric and photometric dataused previously for temperature determinations have been collected. Theinfrared and uvby data were obtained primarily with the objective ofidentifying binaries with dissimilar components among a sample of fieldhalo dwarfs by comparing metallicity insensitive blue and infraredcolors. Attention is given to 111 spectrophotometric scans of 89 stars,67 uvby measures of 41 stars, 127 UBV measures of 87 stars, 147 (RI)Jmeasures of 127 stars, 8 JHK measures of eight stars in the 'HCO'system, and 212 JHK measures of 137 stars in the 'CIT' system. Themajority of these stars are dwarfs, and most of them are metal poor. Theresults of a search for binaries in 71 halo dwarf stars are alsopresented, taking into account a few other dwarfs of special interest.
| Revised MK Spectral Standard Stars Later than G0
Not Available
| Revised MK spectral types for G, K, and M stars
A catalog of spectral types of 552 G, K, and M stars is presented, whichis classified on the revised MK system. Stellar representatives of thehalo, disk, and arm populations in all parts of the sky are included.Photoelectric V magnitudes are given, as are intensity estimates of anyfeatures which make the spectrum appear peculiar as compared to thespectrum of a similar normal star. Abundance indices are also providedin the following lines or bands: CN, barium, Fe, calcium, and CH.
| Cyanogen strengths, mixing and supermetallicity in G and K giants
Wide visual binaries consisting of a G or K giant in physicalassociation with an F dwarf, observed using DDO and ubvy photometry,were used to study the possibility of mixing in the giants prior to orduring helium core burning. The two abundance indices, delta m1 of theuvby system, and delta CN of the DDO system, are compared to study thepossibility that mixing from a hydrogen burning region has affected theCN strengths of the giants.
| On the luminosity criteria relative to late-type stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&A....52..385G&db_key=AST
| Broad-band photometry of G and K stars - The C, M, T/1/, T/2/ photometric system
An alternative broad-band photometric system is described which isdesigned to obtain accurate photometric temperatures, metal abundances,and a cyanogen blanketing index for G and K giants. The filters definingthe system are given along with the effective wavelength of eachbandpass, the bandpass width for one-half maximum responsivity, and theresponse function of the system. A comparison with the UBV broad-bandsystem shows that the C, M, T(1), T(2) system is more efficient since itrequires less observing time to obtain all three parameters than the UBVsystem needs just for two of them. The reduction of observations isoutlined, and the definition of the standard system is described indetail. Results are presented for abundance analyses of 36 G and Kgiants; 23 members of the Hyades, Praesepe, and M67; 7 super-metal-richstars; and also 26 G-type dwarfs. Effects of reddening and luminosity onthe metallicity and CN indices are examined.
| Determination of atmospheric parameters for G and K giants by means of photoelectric indices.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971A&A....15..123H&db_key=AST
| UBV photometry of 550 F, G and K type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966MNRAS.133..475A&db_key=AST
| Hα Photometry of late-type stars I. F, G and K-type stars north of the equator
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1964MNRAS.128..435P&db_key=AST
| Relationship between CN anomaly and U V W components of space velocity.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1962AJ.....67..757Y&db_key=AST
| The magnesium b lines in late-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960MNRAS.121...52D&db_key=AST
| Photoelectric measurements of the λ4200 A CN band and the G band in G8-K5 spectra
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960MNRAS.120..287G&db_key=AST
| Spectral Classification of the High-Velocity Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1953ApJ...117..241K&db_key=AST
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Группы:
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Наблюдательные данные и астрометрия
| Созвездие: | Кассиопея |
| Прямое восхождение: | 00h32m47.53s |
| Склонение: | +54°07'11.8" |
| Видимая звёздная величина: | 6.929 |
| Расстояние: | 280.899 парсек |
| Собственное движение RA: | 74.6 |
| Собственное движение Dec: | -36.6 |
| B-T magnitude: | 8.537 |
| V-T magnitude: | 7.062 |
Каталоги и обозначения:
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