내용
사진
사진 업로드
DSS Images Other Images
관련 글
A catalog of bright calibrator stars for 200-m baseline near-infrared stellar interferometry
We present in this paper a catalog of reference stars suitable forcalibrating infrared interferometric observations. In the K band,visibilities can be calibrated with a precision of 1% on baselines up to200 meters for the whole sky, and up to 300 meters for some part of thesky. This work, extending to longer baselines a previous catalogcompiled by Bordé et al. (2002, A&A, 393, 183), isparticularl y well adapted to hectometric-class interferometers such asthe Very Large Telescope Interferometer (VLTI, Glindemann et al. 2003,Proc. SPIE, 4838, 89) or the CHARA array (ten Brummelaar et al. 2003,Proc. SPIE, 4838, 69) when one is observing well-resolved, high-surfacebrightness objects (K 8). We use the absolute spectro-photometriccalibration method introduced by Cohen et al. (1999, AJ, 117, 1864) toderive the angular diameters of our new set of 948 G8-M0 calibratorstars extracted from the IRAS, 2MASS and MSX catalogs. Angular stellardiameters range from 0.6 mas to 1.8 mas (median is 1.1 mas) with amedian precision of 1.35%. For both the northern and southernhemispheres, the closest calibrator star is always less than 10°away.
| 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}
| Detection of double stars with the use of Kyiv database of lunar occultations
On the basis of 40-year series of observations of occultations of starsby the Moon from the Kyiv database, we found 83 stars which are likelyto be double ones. Additional components close to basic stars arerevealed for four known wide pair.
| 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.
| A homogeneous temperature calibration for K and M giants with an extension to the coolest stars
In this paper we present a new estimate of the effective temperatures of32 giant stars in the spectral range K0 to M10. The sample includes also4 Mira stars. The temperatures are based on a homogeneous set of angulardiameters obtained by our group by the technique of lunar occultations,and using a photometric and spectroscopic coverage with a combination oforiginal measurements and literature data. Most of this basic materialhad been presented in previous papers, but in the present work we deriveimproved effective temperatures by using for the first time a grid ofnumerical center-to-limb darkening models. We use this revision toderive a new calibration of the effective temperature of K and M giantstars, which has the advantage of being based on only one, highlyhomogeneous set of data (while previous calibrations often used mixeddata sets). The resulting calibration is extended to the coolest stars,reaching for the first time M9 for the non-Mira stars, and M10 for theMira stars. In this latter case the calibration does not account forpulsation phase variations and is only tentative. In the region ofoverlap with previously existing calibrations, we find a largelysatisfactory agreement, although some differences exist and arediscussed. In particular, it appears that the calibration of theeffective temperature of cool Mira stars requires additionalobservational as well as theoretical effort. Seven of the stars in oursample appear to exhibit an effective temperature that departssignificantly from the mean relation (~ 900 K cooler between K1 and M8),and no simple explanation in terms of possible bias or experimentalerror could be found. Based on observations collected at TIRGO(Gornergrat, Switzerland), at Calar Alto (Spain) and at the EuropeanSouthern Observatory in La Silla (Chile). TIRGO is operated by CNR --CAISMI Arcetri, Italy. Calar Alto is operated by the German-SpanishAstronomical Center.
| Infrared high angular resolution measurements of stellar sources. III. Angular diameters and effective temperatures of eleven late-type giants
Near-infrared lunar occultation observations of eleven late-type giantsin the spectral range K0 to M6 (including one carbon star) are reportedhere. These stars are resolved from our observations carried out at2.2mu m, resulting in accurate determinations of their angular sizes,with values in the range 1.4 to 7.1 milliseconds of arc (mas) and atypical accuracy of 0.12 mas. Nine out of eleven sources are resolvedfor the first time. In addition, near infrared photometric observationsof some of the sources have been carried out to compute stellarbolometric fluxes, and hence derive the effective temperatures. Ouraccurate angular diameter measurements (at least in the case of eightsources) have the potential to provide effective temperatures with anaccuracy less than 3% when bolometric fluxes become available with anaccuracy less than 10%. The observed sources are discussed inconjunction with earlier high angular resolution observations andavailable photometric data. A comparison of the current performance oflunar occultations and long baseline interferometry in the field ofangular diameters and effective temperatures is presented. Based onobservations collected at TIRGO (Gornergrat, Switzerland), at Calar Alto(Spain), and at the European Southern Observatory (La Silla, Chile).TIRGO is operated by CNR-CAISMI Arcetri, Italy. Calar Alto is operatedby the German-Spanish Astronomical Center.
| New binary stars discovered by lunar occultations. III.
We report on a total of 20 occultation events of 16 binary sources,observed in the near infrared in the course of routine lunar occultationprograms at the TIRGO and Calar Alto observatories. The results consistin either discoveries of new binaries, or in re-observations of known orsuspected binaries where only incomplete information was available. Thispaper is the third in a series of similar reports (see Richichi et al.1994A&A...286..829R and 1996A&A...309..163R, hereafter Papers Iand II). For the following 9 stars, we detected a companion for thefirst time: SAO 160179, DO 10593, DO 11286, SAO 96515, SAO 96547, SAO164323, SAO 164360, SAO 164371, SAO 128391. Of these, SAO 96515 was asuspected lunar occultation binary, while SAO 160179 and SAO 96547 (aswell as SAO 146402 below) belong also to wider binary pairs. For thefollowing 4 stars, we confirm previous reports of binarity: SAO 161153,SAO 95419, SAO 146402, SAO 96810; for these stars, our IR measurementscomplement existing visual information: Finally, in the case of thethree stars SAO 93777, SAO 162050 and SAO 95456, a companion had alsobeen previously observed or suspected, but we could not detect it. Ournegative detection in these cases provides a constraint on thecharacteristics of the companion. The projected separations in ourpositive results cover a range of two orders of magnitude, from =~0.006"to =~0.6".
| The TIRGO Lunar Occultation Program: Summary of the 1985-1995 Observations
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....112.2786R&db_key=AST
| ICCD Speckle Observations of Binary Stars.XV.An Investigation of Lunar Occultation Systems
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....112.2260M&db_key=AST
| 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 preliminary catalogue of stars observed with the photoelectric astrolabe of the Beijing Astronomical Observatory.
Not Available
| UBV photometry of stars whose positions are accurately known.
Photometric indices V, B-V, and U-B were measured for about 560 stars ofthe AGK3R and NPZT catalogs between BD declinations 11 deg and 23 deg,using the 40-cm Cassegrain telescope of the Kvistaberg Observatory fromApril 1986 to May 1987. The observation procedure and the reductiontechnique were the same as in the earlier papers of this series by Oja(1984, 1985, 1986, and 1987). The mean errors were calculated from theinternal consistency of the data. The accuracy was found to be the sameas for the earlier parts of the survey.
| E. W. Fick Observatory stellar radial velocity measurements. I - 1976-1984
Stellar radial velocity observations made with the large vacuumhigh-dispersion photoelectric radial velocity spectrometer at FickObservatory are reported. This includes nearly 2000 late-type starsobserved during 585 nights. Gradual modifications to this instrumentover its first eight years of operation have reduced the observationalerror for high-quality dip observations to + or - 0.8 km/s.
| 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.
| Etude pour chaque champ de l'absorption et de la repartition des vitesses radiales EN fonction de la distance.
Not Available
| La mesure des vitesses radiales au prisme objectif. VII - 2e liste de vitesses radiales déterminées au prisme objectif à vision directe
Not Available
| Mesures de vitesses radiales au spectrographe C de l'Observatoire de Haute Provence
Not Available
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
