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CHARM2: An updated Catalog of High Angular Resolution Measurements
We present an update of the Catalog of High Angular ResolutionMeasurements (CHARM, Richichi & Percheron \cite{CHARM}, A&A,386, 492), which includes results available until July 2004. CHARM2 is acompilation of direct measurements by high angular resolution methods,as well as indirect estimates of stellar diameters. Its main goal is toprovide a reference list of sources which can be used for calibrationand verification observations with long-baseline optical and near-IRinterferometers. Single and binary stars are included, as are complexobjects from circumstellar shells to extragalactic sources. The presentupdate provides an increase of almost a factor of two over the previousedition. Additionally, it includes several corrections and improvements,as well as a cross-check with the valuable public release observationsof the ESO Very Large Telescope Interferometer (VLTI). A total of 8231entries for 3238 unique sources are now present in CHARM2. Thisrepresents an increase of a factor of 3.4 and 2.0, respectively, overthe contents of the previous version of CHARM.The catalog is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/431/773
| 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}
| J - K DENIS photometry of a VLTI-selected sample of bright southern stars
We present a photometric survey of bright southern stars carried outusing the DENIS instrument equipped with attenuating filters. Theobservations were carried out not using the survey mode of DENIS, butwith individual target pointings. This project was stimulated by theneed to obtain near-infrared photometry of stars to be used in earlycommissioning observations of the ESO Very Large TelescopeInterferometer, and in particular to establish a network of brightcalibrator sources.We stress that near-infrared photometry is peculiarly lacking for manybright stars. These stars are saturated in 2MASS as well as in regularDENIS observations. The only other observations available for brightinfrared stars are those of the Two Micron Sky Survey dating from overthirty years ago. These were restricted to declinations above≈-30°, and thus cover only about half of the sky accessible fromthe VLTI site.We note that the final 2MASS data release includes photometry of brightstars, obtained by means of point-spread function fitting. However, thismethod only achieves about 30% accuracy, which is not sufficient formost applications.In this work, we present photometry for over 600 stars, each with atleast one and up to eight measurements, in the J and K filters. Typicalaccuracy is at the level of 0\fm05 and 0\fm04 in the J and K_s bands,respectively.Based on observations collected at the European Southern Observatory, LaSilla.Tables 1 and 2 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?J/A+A/413/1037
| 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
| CHARM: A Catalog of High Angular Resolution Measurements
The Catalog of High Angular Resolution Measurements (CHARM) includesmost of the measurements obtained by the techniques of lunaroccultations and long-baseline interferometry at visual and infraredwavelengths, which have appeared in the literature or have otherwisebeen made public until mid-2001. A total of 2432 measurements of 1625sources are included, along with extensive auxiliary information. Inparticular, visual and infrared photometry is included for almost allthe sources. This has been partly extracted from currently availablecatalogs, and partly obtained specifically for CHARM. The main aim is toprovide a compilation of sources which could be used as calibrators orfor science verification purposes by the new generation of largeground-based facilities such as the ESO Very Large Interferometer andthe Keck Interferometer. The Catalog is available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/386/492, and from theauthors on CD-Rom.
| Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable 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/qcar?J/A+A/367/521
| Angular diameter and effective temperature of a sample of 15M giants at 2.2μm from lunar occultation observations
High angular resolution measurements of a sample of 15M giants at2.2μm by the technique of lunar occultation are presented in thispaper. We obtain angular diameters for 11 sources of which five are thefirst diameter measurements. For these resolved sources we haveestimated the effective temperatures, which are consistent with previouscalibrations. For the other four sources we put the first upper limitson their angular sizes to be 2mas. Two sources, namely IRC+20090 andIRC+20067, yield appreciably low temperatures, which could point totheir possible Mira nature. For sources with Hipparcos parallaxmeasurements, we have calculated the linear radii.
| The 74th Special Name-list of Variable Stars
We present the Name-list introducing GCVS names for 3153 variable starsdiscovered by the Hipparcos mission.
| Near IR lunar occultation observations and results from Gurushikhar observatory
Not Available
| Near infrared occultation studies of late type stars and circumstellar regions from Gurushikhar observatory
Not Available
| Milliarcsecond-resolution observations of M giants in the near-infrared by lunar occultations
Near-infrared lunar occultation observations of six M giants, namelyIRC+20190, NSV 1529, IRC+00198, BQ Ori, IRC+10194 and IRC+10024, in thespectral range M2-M7 are reported. Among these, four giants (NSV 1529,BQ Ori, IRC+10194 and IRC+10024) are resolved from our observationscarried out at 2.2mum, resulting in accurate estimations of the angularsize and the stellar effective temperature of these sources. Thepeculiarity of IRC+10194 and the problem of its real effectivetemperature are discussed. Upper limits on the stellar angular size forthe other two giants have been derived.
| Classification and Identification of IRAS Sources with Low-Resolution Spectra
IRAS low-resolution spectra were extracted for 11,224 IRAS sources.These spectra were classified into astrophysical classes, based on thepresence of emission and absorption features and on the shape of thecontinuum. Counterparts of these IRAS sources in existing optical andinfrared catalogs are identified, and their optical spectral types arelisted if they are known. The correlations between thephotospheric/optical and circumstellar/infrared classification arediscussed.
| The pulsation, temperatures and metallicities of Mira and semiregular variables in different stellar systems
Data on angular diameters and infrared photometry for late-type starsare assembled. It is shown that a consistent T_eff scale can beestablished, combining results for Mira and non-Mira M-type stars. Thelog T_eff versus (J-K) relation is much steeper than previously adopted,but is consistent with predictions from model stellar atmospheres.Comparison of the linear diameters of Miras measured in the red spectralregion with those measured in the infrared shows that modelssuccessfully predict the extension observed in the red, and the combineddata provide strong evidence that Miras are pulsating in their firstovertone. Data on Miras and semiregular (SR) variables in globularclusters are compared with predictions from stellar evolution andpulsation theory. These data also support a steep log T_eff versus (J-K)relation at low temperatures. The Miras and SR variables in 47 Tucconform to theoretical expectation if they are undergoing an averagemass loss of ~3x10^-7 M_ yr^-1. SR variables in both metal-rich andmetal-poor globular clusters are probably pulsating, like the Miras intheir first overtone. The general agreement between observations andtheory now found suggests that infrared colour-period relations can beused to investigate overall metallicity differences between Miras indifferent stellar systems, at least at the shorter periods wherecircumstellar extinction is probably negligible. A comparison of Mirasin Galactic globular clusters of known metallicity with those in the LMCand in the SgrI window of the Galactic Bulge indicates that Miras ofperiods 100 to 300d in the LMC have a mean metallicity log z~-0.6,whilst those in SgrI have log z~-0.2, close to that of K giants in theNGC 6522 Bulge window. No evidence has yet been found for a dependenceof the Mira period-luminosity relation on metallicity, and it is pointedout that theory does not at present give a definitive prediction of suchan effect. Some stars of special interest are discussed in an appendix.
| 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.
| Third list of corrections to the identifications of IRAS sources in Astron. & Astrophys Suppl. 65, 607 and Astron. J. 98, 931
Not Available
| 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.
| A Catalog of Stellar Angular Diameters Measured by Lunar Occultation
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1987AJ.....94..751W&db_key=AST
| 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.
| Chromospheric activity and TiO bands in M giants
Low-resolution IUE spectra of 23 cool giant stars ranging from K3through M6 have been used to examine chromospheric activity in late-typegiants. Previous studies have suggested a decrease in the fractionalflux, normalized to bolometric flux, of the Mg II resonance lines (anindicator of chromospheric activity) with effective temperature. Usingmore accurately determined effective temperatures, this decrease isconfirmed and found to be more rapid than previously suggested. A strongcorrelation is found between relative TiO band strengths, as measured bythe Wing TiO index, and the level of chromospheric activity, as measuredby Mg II fluxes. Cool giants which have weak TiO bands relative to themean TiO strengths for stars of similar color also have Mg II lines thatare weaker than the mean. Changes in composition and in chromosphericactivity as a consequence of aging are suggested as a possible origin ofthis interesting relation.
| Chromospheric activity in M giants
Low resolution IUE spectra were obtained for fifteen cool giant starsranging in spectral type from K4.8 thru M5.9. These spectra were used toexamine chromospheric activity and to evaluate the extent to whichnonradiative heating affects the upper levels of cool giantphotospheres. The stars were chosen because of their well determinedwide band colors, TiO band strengths (from wing photometry), angulardiameters (determined from lunar occultations), apparent bolometricfluxes as seen from Earth, and effective preliminary analysis of theseobservations is presented.
| Spectral energy distribution and effective temperature scale of M-giant stars. II - Application of the infra-red flux method
The stellar effective temperature can be determined on the basis of ananalysis of the shape of the spectral energy distribution curve. Aninvestigation is conducted regarding the possibility of applying theinfrared method for determining stellar effective temperature to K-Mgiant stars. Attention is given to an application of the infrared fluxmethod to cool stars, emergent fluxes and R-values for M-giant stars,effective temperatures of M-giant stars, spectral classification andcolor indices, and the HR diagram of M-giant stars and Mira variables.Several advantages of applying the infrared flux method to K-M giantstars are shown. Difficulties, however, are related to current lists ofspectroscopic data, especially for cool stars. It may, therefore, besafe to confine an application of the infrared flux method at presentonly to the spectral region least disturbed by line absorption.
| Effective temperatures of late-type stars - The field giants from K0 to M6
Angular diameters from lunar occultation are combined with infraredphotometry to determine effective temperatures for K0-M6 giants. Therelations between effective temperature and color temperature, MKspectral type, V-K color, and I(104)-L color are derived. The principalresult is a general increase in effective temperature for the coolerspectral types compared to previous calibrations. Throughout thetemperature range studied, excellent agreement is obtained with recentmodel atmosphere computations.
| Angular diameters by the lunar occultation technique. III
Diameters for 13 stars are reported. Two of these involve simultaneousobservations at two telescopes, and repeat measurements are presentedfor three additional stars. A highly reliable diameter of the carbonstar SZ Sgr is reported, and included in an analysis of the relationshipbetween the effective and color temperatures for carbon stars. Formalerror estimates for the diameters from least-squares solutions arediscussed based on accumulated multiple measurements for 24 stars.
| Twenty-eight angular diameters for late-type stars by the lunar occultation technique
New angular diameter measurements obtained with an infrared photometerare reported. The stars observed include three Mira variables and ninecool IRC objects. Repeat measurements are reported for five stars. Theobservations include numerous daytime and reappearance events. Severalresults obtained with the 4-m telescope verify the value of a largeaperture for the measurement of angular diameters as small as 1.5-2.5milliarcsec.
| Stellar angular diameters and visual surface brightness. III - an improved definition of the relationship
The relation between visual surface brightness and (V-R)(0) is refinedby taking explicit account of the effects of limb darkening, by adding40 new stars to the previous calibration, introducing extensive new BVRIphotometry, and by incorporating additional angular-diametermeasurements. A tight correlation between the visual surface brightnessindex and (V-R)(0) was found to exist over the entire distribution;hence the conclusion is strengthened that (V-R)(0) can be used to infervisual surface brightness for all luminosity classes and spectral types,including S and C types.
| Photoelectric observations of lunar occultations. X
Photoelectric occulation results for 461 events observed during 15months are reported. They include 77 reappearances, 4 determinations ofangular diameter, 38 analyses of double or multiple stars including twopreviously unknown bright stars, and 8 previously known bright double ormultiple stars.
| Angular diameters for 11 late-type stars by the lunar occultation technique
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977AJ.....82..414R&db_key=AST
| A sample of old-disk-population red giants.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976PASP...88..426E&db_key=AST
| 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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Pozíciós és asztrometriai adatok
| Csillagkép: | Rák |
| Rektaszcenzió: | 08h48m39.54s |
| Deklináció: | +12°32'49.0" |
| Vizuális fényesség: | 6.682 |
| Távolság: | 446.429 parszek |
| RA sajátmozgás: | -17.3 |
| Dec sajátmozgás: | -2.4 |
| B-T magnitude: | 8.81 |
| V-T magnitude: | 6.858 |
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