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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Hipparcos red stars in the HpV_T2 and V I_C systems
For Hipparcos M, S, and C spectral type stars, we provide calibratedinstantaneous (epoch) Cousins V - I color indices using newly derivedHpV_T2 photometry. Three new sets of ground-based Cousins V I data havebeen obtained for more than 170 carbon and red M giants. These datasetsin combination with the published sources of V I photometry served toobtain the calibration curves linking Hipparcos/Tycho Hp-V_T2 with theCousins V - I index. In total, 321 carbon stars and 4464 M- and S-typestars have new V - I indices. The standard error of the mean V - I isabout 0.1 mag or better down to Hp~9 although it deteriorates rapidly atfainter magnitudes. These V - I indices can be used to verify thepublished Hipparcos V - I color indices. Thus, we have identified ahandful of new cases where, instead of the real target, a random fieldstar has been observed. A considerable fraction of the DMSA/C and DMSA/Vsolutions for red stars appear not to be warranted. Most likely suchspurious solutions may originate from usage of a heavily biased color inthe astrometric processing.Based on observations from the Hipparcos astrometric satellite operatedby the European Space Agency (ESA 1997).}\fnmsep\thanks{Table 7 is onlyavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/397/997
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UBV(RI)C photometry of Hipparcos red stars
We present homogeneous and standardized UBV(RI)C photometryfor nearly 550 M stars selected from the Hipparcos satellite data baseusing the following selection criteria: lack of obvious variability (noHipparcos variability flag); δ<+10°(V-I)>1.7 and Vmagnitude fainter than about 7.6. Comparisons are made between thecurrent photometry, other ground-based data sets and Hipparcosphotometry. We use linear discriminant analysis to determine aluminosity segregation criterion for late-type stars, and principalcomponent analysis to study the statistical structure of the colourindices and to calibrate absolute magnitude in terms of (V-I) for thedwarf stars. Various methods are used to determine the mean absolutemagnitude of the giant stars. We find 10 dwarf stars, apparentlypreviously unrecognized (prior to Hipparcos) as being within 25pc,including five within 20pc.
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Long period variable stars: galactic populations and infrared luminosity calibrations
In this paper HIPPARCOS astrometric and kinematic data are used tocalibrate both infrared luminosities and kinematical parameters of LongPeriod Variable stars (LPVs). Individual absolute K and IRAS 12 and 25luminosities of 800 LPVs are determined and made available in electronicform. The estimated mean kinematics is analyzed in terms of galacticpopulations. LPVs are found to belong to galactic populations rangingfrom the thin disk to the extended disk. An age range and a lower limitof the initial mass is given for stars of each population. A differenceof 1.3 mag in K for the upper limit of the Asymptotic Giant Branch isfound between the disk and old disk galactic populations, confirming itsdependence on the mass in the main sequence. LPVs with a thin envelopeare distinguished using the estimated mean IRAS luminosities. The levelof attraction (in the classification sense) of each group for the usualclassifying parameters of LPVs (variability and spectral types) isexamined. Table 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/374/968 or via ASTRIDdatabase (http://astrid.graal.univ-montp2.fr).
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The luminosity index for M stars and the distance to the LMC.
Not Available
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Quantitative spectral classification of galactic disc K-M stars from spectrophotometric measurements
New spectral observations for 47 southern galactic red supergiantsobtained with the new RUBIKON spectrophotometer (developed at theAstronomisches Institut der Ruhr-Universitat Bochum) at the Bochum 61-cmtelescope on La Silla are presented. The spectra range from 4800 to 7700A and their resolution is 10 A. The mean error of absolute fluxes is0.028 mag and that of relative fluxes 0.021 mag. The spectra will beavailable at the Strasbourg Stellar Database (CDS). Together with datataken from recently published spectral catalogues, the new observationshave been used to define spectral indices as measures of the strengthsof the following features: Fe i+TiOalpha_1, Mgb+TiOalpha_0,NaD+TiOgamma'_1, TiOgamma'_0 and TiOgamma_1 systems. The indices havebeen checked against errors introduced by reductions, interstellarreddening and different resolutions of different spectral catalogues,and have been found to be very insensitive to all these effects.Therefore, different catalogues may be combined without any loss ofaccuracy and homogeneity. The mean error of a single index has beenfound to be 0.011 mag. For stars from K4 to M7, a strong temperaturedependence is found for all indices. For the Fe i+TiO and especially theMgb+TiO features, a strong dependence on luminosity has also beenobserved. These indices therefore have been combined to form aluminosity index, while the others together form a spectral index. Thecombined indices have been calibrated in terms of MK data using thestepwise linear regression technique, and may be used for quantitativetwo- dimensional spectral classification of late K- and M-type stars.The mean error of the classification is 0.6 of spectral subtype and 0.8of luminosity class, which is much higher than would be expected fromthe uncertainty of the indices alone (which, e.g., for an M4 giantcorrespond to an uncertainty of 0.1 of spectral subtype and 0.3 ofluminosity class). This may be explained by the uncertainty of theoriginal MK classifications and the variability of some programme stars.
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Detection of red supergiant stars on the colour-colour diagrams in the system UBVRI.
Not Available
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UBV photometry of wide visual double stars. V. Double stars with mainly K- and M- type primaries.
We present UBV photometric observations of 55 wide visual double starswith K- and M- type primaries. Our observations have been compared andcombined with information available in the literature. At least 58% ofthem are optical pairs.
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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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Identification of 106 new infrared carbon stars in the IRAS Point Source Catalog - Near-infrared photometry and their space distribution in the galaxy
A method based solely on IR colors - the combination of near-IR and IRAScolors - is used to identify 106 new IR carbon stars (IRCS). It is shownthat the proportion of IRCS in a region of the IRAS two-color diagrampreviously thought to contain the largest concentration of such stars isnot as large as expected for the faintest objects. A local spatialnumber density of about 12 IRCS/sq kpc is estimated. It is shown to beuniform within 5 to 11 kpc from the galactic center. The local ratio ofIRCS to optical carbon stars is found to be about 35 percent. A totalrestitution rate of about 10 to the -4 solar masses/yr/sq kpc isderived. The efficiency of the combination of near and mid-IR photometryfor the study of AGB stars is confirmed.
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Mass-losing M supergiants in the solar neighborhood
A list of the 21 mass-losing red supergiants (20 M type, one G type; Lgreater than 100,000 solar luminosities) within 2.5 kpc of the sun iscompiled. These supergiants are highly evolved descendants ofmain-sequence stars with initial masses larger than 20 solar masses. Thesurface density is between about 1 and 2/sq kpc. As found previously,these stars are much less concentrated toward the Galactic center thanW-R stars, which are also highly evolved massive stars. Although withconsiderable uncertainty, it is estimated that the mass return by the Msupergiants is somewhere between 0.00001 and 0.00003 solar mass/sq kpcyr. In the hemisphere facing the Galactic center there is much less massloss from M supergiants than from W-R stars, but, in the anticenterdirection, the M supergiants return more mass than do the W-R stars. Theduration of the M supergiant phase appears to be between 200,000 and400,000 yr. During this phase, a star of initially at least 20 solarmasses returns perhaps 3-10 solar masses into the interstellar medium.
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A comparative study of NA I and CA II infrared lines in stars, star clusters and galaxy nuclei - an alternative to the dwarf-enriched population
A comparative study is made of the near-infrared Na I doublet and the CaII triplet, among sets of stars, star clusters and galaxy nuclei. Inparticular, the semistellar nucleus of M31 is studied. Evidence is foundthat the enhancement of the absorption feature around 8200 A in galaxynuclei is not due to a strengthening of the Na I lines, but rather toanother absorber, possibly a molecular band at about 8205 A which variesstrongly with Theta(eff) and metallicity. Therefore, an alternativeexplanation to the classical discussion about dwarf/giant star contentin M31, is that of an increased metallicity in the semistellar nucleusof M31, with respect to its bulge or to the nucleus of M32. A similarresult is found from molecular bands in the visible part of thespectrum, like CN and C2 which show highly nonlinear dependences on themetallicity.
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The cool components of symbiotic stars. I - Optical spectral types
An analysis of prominent absorption features on red spectra of symbioticstars is presented. The depths of TiO and VO bands appear to becorrelated with the brightness of the system; this behavior is probablythe result of the secondary star heating the outer atmosphere of thecool giant. New spectral types and luminosity classes for the coolcomponents of symbiotics are derived, and these classifications suggesta division into semidetached systems and detached systems. Mass-lossrates for detached symbiotics, which do not contain Mira variables,remain higher than those estimated for single red giants of the samespectral type, suggesting that the presence of a binary companionenhances mass loss in these objects.
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M supergiants in the Milky Way and the Magellanic Clouds Colors, spectral types, and luminosities
The differences in metal abundances between the Milky Way, LargeMagellanic Cloud (LMC), and Small Magellanic Cloud (SMC) affect most ofthe observable properties of the M supergiants in these galaxies; thosein the SMC (which has the lowest metal abundance) have the earliest meanspectral type, while those of the Milky Way exhibit the latest meanspectral type. This is presently interpreted as a combination of twoeffects of differing metal abundance on the supergiant atmospheres:first, lower abundance stars of a given effective temperature haveearlier MK spectral types due to reduced TiO abundance; second, theHayashi track is shifted to hotter effective temperature at reducedmetal abundance, thereby shifting the mean spectral type still earlier.The fact that the 10-micron excess decreases linearly with metalabundance suggests that mass loss rates are roughly the same for starsin all three galaxies, with the dust-to-gas ratio proportional to metalabundance.
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The infrared CA II triplet - A luminosity indicator for stellar population synthesis
A Reticon detector coupled to a spectrograph was used to scan the Ca IIIR triplet of 62 stars during Nov. 15-19, 1980. The stars scannedspanned the spectral types B to mid-M and four orders of magnitude ingravity and one in metallicity. Strong correlations were found betweenthe Ca II luminosity and log g, strong enough so that g could bedetermined from the Ca magnitude alone. Metal rich stars also generallyexhibited enhanced Ca II emission. Ca II was the strongest feature inthe near-IR region. The Ca II line is concluded a valid indicator ofgiant stars and thus reliable for constraining the dwarf/giant ratio ina stellar population. The conclusion is in accord with the data base onthe population and luminosity of M31.
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New UBVRI photometry for 900 supergiants
A description is presented of the results obtained in connection with asystematic program of supergiant photometry on the Johnson UBVRI system.During the eight years after the start of the program, almost 1000 starshave been observed, about 400 three or more times each. The originalselection of stars used the spectral type catalog of Jaschek et al.(1964) to choose supergiants. Since observations were possible from bothChile and Canada, no declination limits were imposed, and no particularselection criteria were imposed other than to eliminate carbon stars.These are so red as to require enormous extrapolations of thetransformation equations.
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Nineteen new spectroscopic binaries and the rate of binary stars among F-M supergiants
Nineteen spectroscopic binaries (SBs) have been discovered in radialvelocity measurements made with the CORAVEL spectrophotometer on 181northern F-M supergiants. The rate of detected SBs among northern F-Msupergiants is 21 percent, without any dependence on spectral orluminosity class. The study of the binary F-M supergiants with knownorbital elements indicates that all the systems with a period smallerthan the critical value P(circ) have a nearly circular orbit. The valueof P(circ) depends on the luminosity class, being 400-600 d for class Iband 2000-7000 d for class Ia. This circularization of the orbits may bedue to the transfer of angular momentum during the phase of binary massexchange.
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65th Name-List of Variable Stars
Not Available
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Supergiant OH/IR stars
OH was detected toward six stars out of approximately 70 M supergiantsthat were searched for type I OH emissions, but is in most cases thoughtto not be associated with these stars. It is indicated by the results ofthis survey, in combination with earlier searches for Type II OHsupergiants, that OH luminosities are lower for Type I than Type IIsupergiants. Effects similar to a trend toward OH luminosity increaseswith IR color index have been noted for OH Miras, though these starsgenerally have smaller OH luminosities and color indexes. Results arefound to be consistent with OH supergiants having thicker dust envelopesthan most OH Miras.
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New variable M supergiant stars.
Not Available
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Photoelectric two-dimensional spectral classification of M supergiants
A photoelectric system defined by eight narrow bands between 0.7 and 1.1microns has been used to measure nearly all M supergiants that have beenclassified on the MK system. The photometric TiO and CN indicesreproduce the two-dimensional MK classifications to the accuracy of theMK types themselves. Mean fluxes and spectral classifications arepresented for 128 stars.
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The value of R in Monoceros
Recent photometric and spectroscopic observations are used inconjunction with other data for early-type stars in northern Monocerosin order to investigate the local value of R (the ratio of total toselective extinction). From a variable-extinction analysis, it isconcluded that a ratio of approximately 3.2 is appropriate for thegeneral interstellar extinction in this region and that there is noevidence here for the existence of local anomalies. The two majorassociations Mon OB 1 and Mon OB 2 are clearly delineated and are foundto exhibit properties typical of such young stellar groups. Derivedproperties for a few interesting stars are presented.
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Five-channel photometry of cepheids and supergiants in the southern Milky Way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&AS...24..413P&db_key=AST
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Classification of 831 two-micron sky survey sources south of +5 degrees.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975AJ.....80.1011H&db_key=AST
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A luminosity discriminant for red giants and supergiants.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973AJ.....78..477S&db_key=AST
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Catalog of Indidual Radial Velocities, 0h-12h, Measured by Astronomers of the Mount Wilson Observatory
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJS...19..387A&db_key=AST
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Photometry of high-luminosity M-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJ...162..217L&db_key=AST
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The space distribution and kinematics of supergiants
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970AJ.....75..602H&db_key=AST
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The Distribution of the BD M-Type Stars Along the Galactic Equator.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1958ApJ...128..510N&db_key=AST
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Reddened Early m- and S-Type Stars in Two Galactic Zones.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1957ApJ...125..408B&db_key=AST
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INHABITED SKY
