|Speckle Interferometry of Southern Double Stars. II. Measures from the CASLEO 2.15 Meter Telescope, 1995-1996|
Relative astrometry is presented for 198 observations of 160 doublestars. The data were obtained at the 2.15 m telescope at the ComplejoAstronómico El Leoncito (Argentina) with a multianodemicrochannel array (MAMA) detector system. Five high-qualitynondetections are also reported. When judged against ephemeris positionsfor binaries with very well determined orbits, the separation residualsexhibit a root mean square deviation of13.2+3.4-1.9 mas and the position angle residualsexhibit rms deviation of 2.9d+0.8d-0.5d. Factorsaffecting the measurement precision are discussed.
|The long-period companions of multiple stars tend to have moderate eccentricities|
We examined the statistics of an angle gamma between the radius vectorof a visual companion of a multiple star and the vector of its apparentrelative motion in the system. Its distribution f(gamma ) is related tothe orbital eccentricity distribution in the investigated sample. Wefound that for the wide physical subsystems of the 174 objects from theMultiple Star Catalogue f(gamma ) is bell-shaped. The Monte-Carlosimulations have shown that our f(gamma ) corresponds to the populationof the moderate-eccentricity orbits and is not compatible with thelinear distribution f(e)=2e which follows from stellar dynamics andseems to hold for wide binaries. This points to the absence of highlyelongated orbits among the outer subsystems of multiple stars. Theconstraint of dynamical stability of triple systems is not sufficient toexplain the ``rounded-off'' outer orbits; instead, we speculate that itcan result from the angular momentum exchange in multiple systems duringtheir early evolution.
|CCD Speckle Observations of Binary Stars from the Southern Hemisphere. II. Measures from the Lowell-Tololo Telescope during 1999|
Speckle observations of 145 double stars and suspected double stars arepresented and discussed. On the basis of multiple observations, a totalof 280 position angle and separation measures are determined, as well as23 high-quality nondetections. All observations were taken with the(unintensified) Rochester Institute of Technology fast-readout CCDcamera mounted on the Lowell-Tololo 61 cm telescope at the Cerro TololoInter-American Observatory during 1999 October. We find that themeasures, when judged as a whole against ephemeris positions of binarieswith very well-known orbits, have root mean square deviations of1.8d+/-0.3d in position angle and 13+/-2 mas in separation. Elevendouble stars discovered by Hipparcos were also successfully observed,and the change in position angle and/or separation since the Hipparcosobservations was substantial in three cases.
|Two-colour photometry for 9473 components of close Hipparcos double and multiple stars|
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
|The ROSAT all-sky survey catalogue of optically bright main-sequence stars and subgiant stars|
We present X-ray data for all main-sequence and subgiant stars ofspectral types A, F, G, and K and luminosity classes IV and V listed inthe Bright Star Catalogue that have been detected as X-ray sources inthe ROSAT all-sky survey; several stars without luminosity class arealso included. The catalogue contains 980 entries yielding an averagedetection rate of 32 percent. In addition to count rates, sourcedetection parameters, hardness ratios, and X-ray fluxes we also listX-ray luminosities derived from Hipparcos parallaxes. The catalogue isalso available in electronic form via anonymous ftp tocdsarc.u-strasbg.fr (126.96.36.199) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
|MSC - a catalogue of physical multiple stars|
The MSC catalogue contains data on 612 physical multiple stars ofmultiplicity 3 to 7 which are hierarchical with few exceptions. Orbitalperiods, angular separations and mass ratios are estimated for eachsub-system. Orbital elements are given when available. The catalogue canbe accessed through CDS (Strasbourg). Half of the systems are within 100pc from the Sun. The comparison of the periods of close and widesub-systems reveals that there is no preferred period ratio and allpossible combinations of periods are found. The distribution of thelogarithms of short periods is bimodal, probably due to observationalselection. In 82\% of triple stars the close sub-system is related tothe primary of a wide pair. However, the analysis of mass ratiodistribution gives some support to the idea that component masses areindependently selected from the Salpeter mass function. Orbits of wideand close sub-systems are not always coplanar, although thecorresponding orbital angular momentum vectors do show a weak tendencyof alignment. Some observational programs based on the MSC aresuggested. Tables 2 and 3 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (188.8.131.52) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
|Photographic observations of visual double stars.|
We present the results of photographic observations of 399 visual doublestars of the Hipparcos Input Catalogue (HIC), observed in the years 1980and 1990-1991 with the 60-cm double-refractor of the Bosscha Observatoryat Lembang, Java.
|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.
|Optical Polarization of 1000 Stars Within 50-PARSECS from the Sun|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&AS..101..551L&db_key=AST
|Micrometric measurements of visual binaries (5th list)|
The data resulting from 596 micrometric measurements of 152 binaries areset forth which represent observations taken on the GPO astrograph(described by Scardia, 1990). The traditional declination method is usedto track star position, and some of the measurements are related toprevious work by the author (1990). The data given include O-Cmeasurements corresponding to the Worley and Heintz catalogue (1984) andother relevant data.
|Photographic observations of visual double stars|
Results are presented of photographic observations of 186 pairs ofvisual double stars, carried out with the 60-cm visual refractor of theBosscha Observatory at Lembang (Java) between 1984 and 1986. Theprocedures used in observations, measurements, and reducing wereidentical to those described by van Albada-van Dien (1983).
|The early F-type stars - Refined classification, confrontation with Stromgren photometry, and the effects of rotation|
The classification for early F-type stars in the MK spectralclassification system presented by Gray and Garrison (1987) is refined.The effect of rotation on spectral classification and ubvy-betaphotometry of early F-type stars is examined. It is found that theclassical luminosity criterion, the 4417 A/4481 A ratio givesinconsistent results. It is shown that most of the stars in the DeltaDelphini class of metallic-line stars are either normal or areindistinguishable from proto-Am stars. It is suggested that thedesignation Delta Delphini should be dropped. The classifications arecompared with Stromgren photometry. The effects of rotation on thedelta-c1 index in the early-F field dwarfs is demonstrated.
|Metallicism among A and F giant stars|
132 stars considered as A and F giants have been studied for theirproperties in the Geneva photometric system. It is shown that thissystem to derive the temperature, absolute magnitude and Fe/H value forstars in this part of the HR diagram. 36 percent of the stars of oursample exhibit an enhanced value Delta m2 that can be interpreted interms of Fe/H. The red limit of stars having an enhanced Fe/H value is0.225 in B2-V1 or 6500 K in Teff. This corresponds to the limit definedby Vauclair and Vauclair (1982) where the diffusion timescale is equalto the stellar lifetime and permits the assumption that the diffusion isthe process responsible for the metallicism observed in the A and Fgiants.
|Micrometric measurements of southern double stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1983A&AS...53..177A&db_key=AST
|Properties of Am, Delta Del and Delta SCT stars in the VBLUW system|
The spread with respect to the main sequence in the two-color diagramsfor 115 Am, Delta Del and Delta Sct, for which VBLUW photometricobservations have been obtained, is primarily attributed to gravityeffects. Exceptions to this rule can be recognized from a comparison oftheir positions in these diagrams and in the reddening-independentdiagram L-U/B-L, where some Delta Sct stars have experienced relativelyhigh reddenings, while others are presumably metal-poor. It is notedthat gravities and temperatures compare satisfactorily with those ofDavis Philip et al. (1976), which were based on uvby-beta photometry.
|Standard Stars for Hα Photometry|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1981A&AS...44..337S&db_key=AST
|Erratum - Discordances Between SAO and HD Numbers for Bright Stars|
|Photometric differences of magnitude in southern double stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&A....84..108F&db_key=AST
|Absolute luminosity calibration of F stars|
Luminosity calibrations are performed for a restricted sample of 706F-type field stars of all luminosity classes and a similarly restrictedsample of 251 main-sequence F stars. The samples are restricted withrespect to values of photometric and metallicity indices, propermotions, radial velocities, and apparent magnitudes. Both linear andsecond-order relations between absolute magnitude and the photometricindices beta, /c1/ or (b-y), /c1/ are considered.These relations are calibrated by the statistical parallax method basedon the principle of maximum likelihood. The possible effect ofinterstellar absorption on the calibration results is investigated alongwith an effect of a photometric correction to the absolute magnitudes.The results obtained are compared with those of Crawford (1975) as wellas with the trigonometric parallaxes. The coefficients of thecalibration relations are derived from the trigonometric parallaxes, andpoor agreement is indicated. It is concluded that the trigonometricparallaxes must be used very carefully and only for nearby stars.
|Detection of errors in spectral classification by cluster analysis|
Cluster analysis methods are applied to the photometric catalogue ofuvby-beta measurements by Hauck and Lindemann (1973) and point out 249stars the spectral type of which should be reconsidered or thephotometric indices of which should be redetermined.
|UVBY beta photometry and MK spectral classification.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&AS...24...69O&db_key=AST
|Optical polarization of stars of galactic latitudes b-45 degres.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&AS...23..125S&db_key=AST
|Classification of Some Bright F-Type Stars with Unusual Spectra|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973PASP...85..328M&db_key=AST
|Rotational Velocities and Spectral Types of Some A-Type Stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972PASP...84..584L&db_key=AST
|Four-colour and H-beta photometry for bright stars in the southern hemisphere.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970AJ.....75..624C&db_key=AST
|BVRI Photometry of 46 Southern Bright Stars|
We have made four color photometric observations (BVRI System) of 46Southern Bright Stars, in order to enlarge, in right ascension, ourprevious Catalogue (Mendoza, 1967a).
|Stellar radial velocities from coudé spectrograms|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968MNRAS.139..341B&db_key=AST
|H_alpha Photometry of Late-type Stars. II. F and G Type Dwarf Stars South of the Equator|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966MNRAS.131..467P&db_key=AST
|Southern Cepheid Photometry.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJS....6..253I&db_key=AST
|Fundamental data for southern stars (First list)|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1957MNRAS.117..534E&db_key=AST