내용
사진
사진 업로드
DSS Images Other Images
관련 글
V474 Car: A Rare Halo RS CVn Binary in Retrograde Galactic Orbit
We report the discovery that the star V474 Car is an extremely active,high velocity halo RS CVn system. The star was originally identified asa possible pre-main-sequence star in Carina, given its enhanced stellaractivity, rapid rotation (10.3 days), enhanced Li, and absolutemagnitude which places it above the main sequence (MS). However, itsextreme radial velocity (264 km s-1) suggested thatthis system was unlike any previously known pre-MS system. Our detailedspectroscopic analysis of echelle spectra taken with the CTIO 4 m findsthat V474 Car is both a spectroscopic binary with an orbital periodsimilar to the photometric rotation period and metal-poor ([Fe/H]sime-0.99). The star's Galactic orbit is extremely eccentric (e ~=0.93) with a perigalacticon of only ~0.3 kpc of the Galacticcenter—and the eccentricity and smallness of its perigalacticonare surpassed by only ~0.05% of local F/G-type field stars. Theobserved characteristics are consistent with V474 Car being ahigh-velocity, metal-poor, tidally locked, chromospherically activebinary, i.e., a halo RS CVn binary, and one of only a few such specimensknown.
| Distance determination for RAVE stars using stellar models
Aims: We develop a method for deriving distances fromspectroscopic data and obtaining full 6D phase-space coordinates for theRAVE survey's second data release. Methods: We used stellarmodels combined with atmospheric properties from RAVE (effectivetemperature, surface gravity and metallicity) and (J-Ks)photometry from archival sources to derive absolute magnitudes. Incombination with apparent magnitudes, sky coordinates, proper motionsfrom a variety of sources and radial velocities from RAVE, we are ableto derive the full 6D phase-space coordinates for a large sample of RAVEstars. This method is tested with artificial data, Hipparcostrigonometric parallaxes and observations of the open cluster M 67. Results: When we applied our method to a set of 16 146 stars, wefound that 25% (4037) of the stars have relative (statistical) distanceerrors of <35%, while 50% (8073) and 75% (12 110) have relative(statistical) errors smaller than 45% and 50%, respectively. Our varioustests show that we can reliably estimate distances for main-sequencestars, but there is an indication of potential systematic problems withgiant stars owing to uncertainties in the underlying stellar models. Forthe main-sequence star sample (defined as those with log(g) > 4), 25%(1744) have relative distance errors <31%, while 50% (3488) and 75%(5231) have relative errors smaller than 36% and 42%, respectively. Ourfull dataset shows the expected decrease in the metallicity of stars asa function of distance from the Galactic plane. The known kinematicsubstructures in the U and V velocity components of nearby dwarf starsare apparent in our dataset, confirming the accuracy of our data and thereliability of our technique. We provide independent measurements of theorientation of the UV velocity ellipsoid and of the solar motion, andthey are in very good agreement with previous work. Conclusions:The distance catalogue for the RAVE second data release is available athttp://www.astro.rug.nl/~rave,and will be updated in the future to include new data releases.
| Calibration of Strömgren uvby-H? photometry for late-type stars - a model atmosphere approach
Context: The use of model atmospheres for deriving stellar fundamentalparameters, such as T_eff, log g, and [Fe/H], will increase as we findand explore extreme stellar populations where empirical calibrations arenot yet available. Moreover, calibrations for upcoming large satellitemissions of new spectrophotometric indices, similar to the uvby-H?system, will be needed. Aims: We aim to test the power oftheoretical calibrations based on a new generation of MARCS models bycomparisons with observational photomteric data. Methods: Wecalculated synthetic uvby-H? colour indices from synthetic spectra.A sample of 367 field stars, as well as stars in globular clusters, isused for a direct comparison of the synthetic indices versus empiricaldata and for scrutinizing the possibilities of theoretical calibrationsfor temperature, metallicity, and gravity. Results: We show thatthe temperature sensitivity of the synthetic (b-y) colour is very closeto its empirical counterpart, whereas the temperature scale based uponH? shows a slight offset. The theoretical metallicity sensitivityof the m1 index (and for G-type stars its combination withc_1) is somewhat higher than the empirical one, based upon spectroscopicdeterminations. The gravity sensitivity of the synthetic c1index shows satisfactory behaviour when compared to obervations of Fstars. For stars cooler than the sun, a deviation is significant in thec1-(b-y) diagram. The theoretical calibrations of (b-y),(v-y), and c1 seem to work well for Pop II stars and lead toeffective temperatures for globular cluster stars supporting recentclaims that atomic diffusion occurs in stars near the turnoff point ofNGC 6397. Conclusions: Synthetic colours of stellar atmospherescan indeed be used, in many cases, to derive reliable fundamentalstellar parameters. The deviations seen when compared to observationaldata could be due to incomplete linelists but are possibly also due tothe effects of assuming plane-parallell or spherical geometry and LTE.Model colours 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/498/527
| Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| Effective temperature scale and bolometric corrections from 2MASS photometry
We present a method to determine effective temperatures, angularsemi-diameters and bolometric corrections for population I and II FGKtype stars based on V and 2MASS IR photometry. Accurate calibration isaccomplished by using a sample of solar analogues, whose averagetemperature is assumed to be equal to the solar effective temperature of5777 K. By taking into account all possible sources of error we estimateassociated uncertainties to better than 1% in effective temperature andin the range 1.0-2.5% in angular semi-diameter for unreddened stars.Comparison of our new temperatures with other determinations extractedfrom the literature indicates, in general, remarkably good agreement.These results suggest that the effective temperaure scale of FGK starsis currently established with an accuracy better than 0.5%-1%. Theapplication of the method to a sample of 10 999 dwarfs in the Hipparcoscatalogue allows us to define temperature and bolometric correction (Kband) calibrations as a function of (V-K), [m/H] and log g. Bolometriccorrections in the V and K bands as a function of T_eff, [m/H] and log gare also given. We provide effective temperatures, angularsemi-diameters, radii and bolometric corrections in the V and K bandsfor the 10 999 FGK stars in our sample with the correspondinguncertainties.
| Galactic model parameters for field giants separated from field dwarfs by their 2MASS and V apparent magnitudes
We present a method which separates field dwarfs and field giants bytheir 2MASS and V apparent magnitudes. This method is based onspectroscopically selected standards and is hence reliable. We appliedit to stars in two fields, SA 54 and SA 82, and we estimated a full setof Galactic model parameters for giants including their total localspace density. Our results are in agreement with the ones given in therecent literature.
| A Survey of Proper-Motion Stars. XVII. A Deficiency of Binary Stars on Retrograde Galactic Orbits and the Possibility that ω Centauri is Related to the Effect
We compare the frequency of field binary stars as a function of Galacticvelocity vectors and find a deficiency of such stars on stronglyretrograde orbits. Metal-poor stars moving on prograde Galactic orbitshave a binary frequency of 28%+/-3%, whereas the retrograde stars'binary frequency is only 10%+/-2% for V<=-300 km s-1. Nosuch binary deficiencies are seen for the U or W velocities, nor for[Fe/H]. Some mechanism exists that either disrupts binary systems orpreferentially adds single stars moving primarily on retrograde orbits.Theoretical analyses and critical evaluations of our observational dataappear to rule out preferential disruption of preexisting binary starsdue to such causes as tidal interactions with massive gravitationalperturbers, including giant molecular clouds, black holes, or theGalactic center.Dynamically evolved stellar ensembles, such as globular clusters,provide a possible source of single stars. Three lines of evidence ruleout this explanation. First, there is no mechanism to significantlyenhance dissolution of clusters moving on retrograde orbits. Second, astudy of globular clusters moving on prograde and retrograde orbits andwith perigalacticon distances such that they are unlikely to be affectedstrongly by central tidal effects shows that clusters moving on progradeGalactic orbits may be more evolved dynamically than clusters moving onretrograde orbits. Finally, we have undertaken a comprehensive searchfor star streams that might be discernible. Monte Carlo modelingsuggests that our sample may include one moving group, but it containsonly five stars. Although the Galactic orbit of this group passes nearthe Galactic center, it is not moving on a retrograde Galactic orbit andfalls short by a factor of at least 20 in supplying the necessary numberof single stars.There is one intriguing possibility to explain our results. A dissolveddwarf galaxy may have too large a velocity spread to be easily detectedin our sample using our technique. However, dwarf galaxies appear tooften show element-to-iron versus [Fe/H] abundance patterns that are notsimilar to the bulk of the stellar field and cluster halo stars. Weexplore the s-process elements Y and Ba. Eight stars in our sample havesuch elemental abundances already measured and also lie in the criticaldomain with -1.6<=[Fe/H]<=-1.0 and V<=-300 km s-1.The admittedly small samples appears to show a bimodal distribution in[Y/Fe], [Ba/Fe], and [α/Fe], where ``α'' represents anaverage abundance of Mg, Si, Ca, and Ti. This behavior is reminiscent ofthe difference in the abundances found between the globular clusterω Centauri and other globular clusters. It is also intriguing thatthe stars most similar to ω Cen in their chemical abundances showa relatively coherent set of kinematic properties, with a modestvelocity dispersion. The stars less like ω Cen define adynamically hot population. The binary frequency of the stars in ωCen does not appear to be enhanced, but detailed modeling of the radialvelocity data remains to be done.
| Improved Astrometry and Photometry for the Luyten Catalog. II. Faint Stars and the Revised Catalog
We complete construction of a catalog containing improved astrometry andnew optical/infrared photometry for the vast majority of NLTT starslying in the overlap of regions covered by POSS I and by the secondincremental Two Micron All Sky Survey (2MASS) release, approximately 44%of the sky. The epoch 2000 positions are typically accurate to 130 mas,the proper motions to 5.5 mas yr-1, and the V-J colors to0.25 mag. Relative proper motions of binary components are measured to 3mas yr-1. The false-identification rate is ~1% for11<~V<~18 and substantially less at brighter magnitudes. Theseimprovements permit the construction of a reduced proper-motion diagramthat, for the first time, allows one to classify NLTT stars intomain-sequence (MS) stars, subdwarfs (SDs), and white dwarfs (WDs). We inturn use this diagram to analyze the properties of both our catalog andthe NLTT catalog on which it is based. In sharp contrast to popularbelief, we find that NLTT incompleteness in the plane is almostcompletely concentrated in MS stars, and that SDs and WDs are detectedalmost uniformly over the sky δ>-33deg. Our catalogwill therefore provide a powerful tool to probe these populationsstatistically, as well as to reliably identify individual SDs and WDs.
| Catalogue of [Fe/H] determinations for FGK stars: 2001 edition
The catalogue presented here is a compilation of published atmosphericparameters (Teff, log g, [Fe/H]) obtained from highresolution, high signal-to-noise spectroscopic observations. This newedition has changed compared to the five previous versions. It is nowrestricted to intermediate and low mass stars (F, G and K stars). Itcontains 6354 determinations of (Teff, log g, [Fe/H]) for3356 stars, including 909 stars in 79 stellar systems. The literature iscomplete between January 1980 and December 2000 and includes 378references. The catalogue is made up of two tables, one for field starsand one for stars in galactic associations, open and globular clustersand external galaxies. The catalogue is distributed through the CDSdatabase. Access to the catalogue with cross-identification to othersets of data is also possible with VizieR (Ochsenbein et al.\cite{och00}). The catalogue (Tables 1 and 2) is only available inelectronic form at the 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/373/159 and VizieRhttp://vizier.u-strasbg.fr/.
| Kinematics of Metal-poor Stars in the Galaxy. II. Proper Motions for a Large Nonkinematically Selected Sample
We present a revised catalog of 2106 Galactic stars, selected withoutkinematic bias and with available radial velocities, distance estimates,and metal abundances in the range -4.0<=[Fe/H]<=0.0. This updateof the 1995 Beers & Sommer-Larsen catalog includes newly derivedhomogeneous photometric distance estimates, revised radial velocitiesfor a number of stars with recently obtained high-resolution spectra,and refined metallicities for stars originally identified in the HKobjective-prism survey (which account for nearly half of the catalog)based on a recent recalibration. A subset of 1258 stars in this cataloghave available proper motions based on measurements obtained with theHipparcos astrometry satellite or taken from the updated AstrographicCatalogue (second epoch positions from either the Hubble Space TelescopeGuide Star Catalog or the Tycho Catalogue), the Yale/San Juan SouthernProper Motion Catalog 2.0, and the Lick Northern Proper Motion Catalog.Our present catalog includes 388 RR Lyrae variables (182 of which arenewly added), 38 variables of other types, and 1680 nonvariables, withdistances in the range 0.1 to 40 kpc.
| The Abundance of CN. Calcium and Heavy Elements in High Velocity Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114..825E&db_key=AST
| A catalogue of [Fe/H] determinations: 1996 edition
A fifth Edition of the Catalogue of [Fe/H] determinations is presentedherewith. It contains 5946 determinations for 3247 stars, including 751stars in 84 associations, clusters or galaxies. The literature iscomplete up to December 1995. The 700 bibliographical referencescorrespond to [Fe/H] determinations obtained from high resolutionspectroscopic observations and detailed analyses, most of them carriedout with the help of model-atmospheres. The Catalogue is made up ofthree formatted files: File 1: field stars, File 2: stars in galacticassociations and clusters, and stars in SMC, LMC, M33, File 3: numberedlist of bibliographical references The three files are only available inelectronic form at the Centre de Donnees Stellaires in Strasbourg, viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5), or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| ROSAT all-sky survey observations of PopII field binaries: X-ray activity of old, metal-poor stellar coronae.
This study represents the first X-ray observations of an extended sampleof Pop II field binaries, aimed at investigating the properties of old,metal-poor stellar coronae. Analysing X-ray observations from the ROSATall-sky survey, we detected only 13 (out of 86) Pop II systems (15%detection rate). The X-ray luminosity function, taking into account bothdetections and upper limits, has its median at logL_x_<=28.1erg/s,indicating a low average X-ray luminosity, with a high-luminosity tailat logL_x_~29-31erg/s. The only extreme metal-poor system detected is HD89499. Thus, the detection rate of extreme Pop II systems is lower thanof intermediate Pop II, possibly indicating extreme Pop II to betypically less luminous. The X-ray luminosity is not very wellcorrelated with orbital period; long-period Pop II binaries may havehigh X-ray luminosities and, surprisingly, short-period systems are notper se strong X-ray emitters. For a subsample of emission-line Pop IIbinaries, i.e. the halo component analogs to the RS CVn binaries, themedian X-ray luminosity is at least one order of magnitude lower thanfor the RS CVns. The lower activity levels of the Pop II systems may becaused in part by the presence of fewer evolved stars in the sample andlower metallicity. The extremely old age of Pop II binaries may alsogive rise to the unexpectedly low X-ray luminosities of some systems(e.g., CD-481741, BD+53080).
| The Ross 451 Group of Halo Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....112.2661E&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.
| Lithium in Short-Period Tidally Locked Binaries: A Test of Rotationally Induced Mixing
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJ...453..819R&db_key=AST
| Ca II H and K Filter Photometry on the UVBY System. II. The Catalog of Observations
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995AJ....109.2828T&db_key=AST
| The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars
The Henry Draper Extension Charts (HDEC), published in the form offinding charts, provide spectral classification for some 87000 starsmostly between 10th and 11th magnitude. This data, being highlyvaluable, as yet was practically unusable for modern computer-basedastronomy. An earlier pilot project (Roeser et al. 1991) demonstrated apossibility to convert this into a star catalogue, using measurements ofcartesian coordinates of stars on the charts and positions of theAstrographic Catalogue (AC) for subsequent identification. We presenthere a final HDEC catalogue comprising accurate positions, propermotions, magnitudes and spectral classes for 86933 stars of the HenryDraper Extension Charts.
| Kinematics of metal-poor stars in the galaxy
We discuss the kinematic properties of a sample of 1936 Galactic stars,selected without kinematic bias, and with abundances (Fe/H) is less thanor equal to -0.6. The stars selected for this study all have measuredradial velocities, and the majority have abundances determined fromspectroscopic or narrow-/intermediate-band photometric techniques. Incontrast to previous examinations of the kinematics of the metal-poorstars in the Galaxy, our sample contains large numbers of stars that arelocated at distances in excess of 1 kpc from the Galactic plane. Thus, amuch clearer picture of the nature of the metal-deficient populations inthe Galaxy can now be drawn.
| Lithium in metal deficient binaries
Not Available
| The general catalogue of trigonometric [stellar] paralaxes
Not Available
| Lithium in old binary stars.
Through a detailed analysis of high resolution, high signal to noisespectra, the lithium abundance of sixteen metal deficient binaries(-2.9<=[Fe/H]<=-0.4) with periods ranging from 220d to 1.8d hasbeen measured. All these stars were supposed to be dwarfs. A carefuldetermination of the atmospheric parameters revealed that some of themwere slightly evolved. However all the stars here studied (but one: HD89499) are in the interval 4900>=T_eff_<=6200K, logg>=3. Thestars are divided in two groups: old disk stars(-1.1<=[Fe/H]<=-0.4) and halo stars ([Fe/H]<=-1.4). The presentanalysis which includes for most of the stars a careful determination ofthe stellar physical parameters (T_eff_ , logg, and [Fe/H]) shows thatfor T_eff_ >= about 5000K the lithium abundance in long and shortperiod binaries does not differ from that of single dwarfs in the sameinterval of temperature, gravity and metallicity. When T_eff_ is <=about 5100K the lithium abundance is larger in the short period binaries(which often have larger values of v sini ). Due to the very smallnumber of metal deficient short period binaries, the limit intemperature is rather uncertain and moreover it may depend on themetallicity of the stars. These results, if confirmed by a larger samplewould cast some doubts on theories predicting a strong Li depletion inold warm stars (and in particular in Pop II dwarfs) induced by strongangular momentum losses.
| Chromospheric activity in Population II binaries
We analyze Ca II and H-alpha observations for a smaple of 27 Pop IIbinaries to investigate their degree of chromospheric activity. We findthat Pop II binaries having periods shorter than around 10 days possessactive chromospheres. On the other hand binaries with longer periodsappear to be chromospherically quiet. Only one object clearly deviatesfrom this trend and our high resolution spectroscopic observationsreveal that this system contains an evolved star. We interpret theseresults as a clear sign that the nature of chromospheric activity in PopII binaries is of magnetic origin, powered by the tidal forces acting inthe short period systems. In this context activity can be a powerfultool to investigate the dynamical evolution of binary systems. The rapiddecay of chromospheric activity with increasing orbital period maysuggest that a minimum rotational velocity is necessary to trigger theonset of a powerful dynamo. Ca II and K observations can also be used todetermine more precise orbits, in fact in two systems previouslyclassified as single line spectroscopic binaries, the Ca II emission ofthe unseen companions is detected. Wilson-Bappu widths are measured for12 stars which may be used to derive additional information on thecomponents of the system.
| Subdwarf Studies. III. The Halo Metallicity Distribution
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1991AJ....101.1865R&db_key=AST
| Subdwarf studies. II - Abundances and kinematics from medium resolution spectra. III - The halo metallicity distribution
Stars previously identified as having UV excesses are observed at 1-Aresolution in the Ca II K-line region. Comparisons of these data withother samples and with Monte Carlo simulations involving a singlecomponent halo have yielded estimates of halo velocity dispersions androtation velocity, corrected for the kinematic biases in the sample. Itis suggested that the data are not consistent with a model in which thehalo formed from star formation in a dissipating, collapsing cloud; theyare, however, reconcilable with the formation of the halo stars bynumerous, independently evolving gas clouds. The metallicitydistribution of a sample of 372 kinematically selected halo stars isthen constructed, with a view to selection effects in the data. Goodagreement is noted between the globular cluster metallicity distributionand a stochastic model with a mean of 10 enrichments/fragment.
| Estimation of stellar metal abundance. I - Calibration of the CA II K index
A method for estimating the stellar metal abundances is proposed whichcompares measures of the equivalent width of a single feature inmoderate resolution (1 A) optical spectra of stars, the Ca II K line at3933 A, with models of the predicted line strength as a function of thebroadband B-V color and Fe/H. The approach is capable of providingestimates of stellar metallicity over the range -4.5 to -1.0 with ascatter of about 0.15 dex for dwarfs and giants in the color range0.33-0.85. For cooler stars, with B-V in the range 0.85-1.1, the scattermay be as large as 0.19 dex. The calibration of the Ca II K index withFe/H is discussed, and average radial velocities and abundances arepresented for several galactic globular clusters.
| Armchair cartography - A map of the Galactic halo based on observations of local, metal-poor stars
The velocity distribution of metal-poor halo stars in the solarneighborhood is studied to extract data on the global spatial andkinematic properties of the Galactic stellar halo. A global model of thesolar neighborhood stars is constructed from observed positions andthree-dimensional velocity of local, metal-poor halo stars in terms of adiscrete sum of orbits. The characteristics of the reconstructed haloare examined and used to study the evolution of the halo subsystems.
| Subdwarf studies. I - UBVRI photometry of NLTT stars
UBVRI photometry is presented for a sample of 1656 southern stars,including 1211 that were previously unmeasured, drown from the NLTTproper-motion catalog. The catalog is shown to be a rich source ofsubdwarfs. The normalized ultraviolet excess delta (U - B)0.6,photometric parallax, and interstellar reddening are calculated for eachstar when possible. Photometric parallaxes are compared withtrigonometric parallaxes from the literature. It is found that theformer do not have systematic errors greater than about 25 percent. Inagreement with other studies, the bluest subdwarfs are found at B - V =0.35. The selection of the program stars on the basis of large reducedproper motions restricted subgiant contamination of the sample to about5 percent and increased the discovery fraction of halo stars relative todisk stars. The claim is made here that the sample can be used toinvestigate the abundance distribution of the halo. The sample includesstars with ultraviolet excesses characteristic of disk abundances butwith velocities up to 150 km/s. These are believed to be stars that,quite expectedly, reside in the high-velocity tail of the disk velocitydistribution.
| Ubvy-beta photometry of high-velocity and metal-poor stars. III - Metallicities and ages of the halo stars
The interstellar color excesses, E(b-y) and the metallicities, Fe/Habundance ratio, are determined for the 711 high-velocity and metal-poorstars in the catalog of ubvy-beta photometry compiled by Schuster andNissen (1988). It is found that 220 of these are halo stars and that 15percent of these halo stars have colors that are significantly affectedby interstellar reddening. A minimum age of 18-20 Gyr is determined forthe halo stars. The results suggest that a pressure-supported slowuniform collapse controlled the formation and evolution of the Galaxy.
| Radial velocity measurements of a sample of northern metal-deficient stars
Observations of 41 northern stars with Fe/H between -1.1 and -0.3,obtained with the Coravel radial-velocity scanner on the 1-m Swisstelescope at the Observatoire de Haute Provence during 1977-1986, arereported. The data are presented in extensive tables and graphs andcharacterized in detail. Seven stars are identified as spectroscopicbinaries, and their distribution as a function of period is shown to besimilar to that for a sample of metal-rich G stars. The present radialvelocities are found to be in relatively good agreement with those ofCarney and Latham (1987), but not with those of Stryker et al. (1985).
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
