Statistical Constraints for Astrometric Binaries with Nonlinear Motion
Useful constraints on the orbits and mass ratios of astrometric binariesin the Hipparcos catalog are derived from the measured proper motiondifferences of Hipparcos and Tycho-2 (Δμ), accelerations ofproper motions (μ˙), and second derivatives of proper motions(μ̈). It is shown how, in some cases, statistical bounds can beestimated for the masses of the secondary components. Two catalogs ofastrometric binaries are generated, one of binaries with significantproper motion differences and the other of binaries with significantaccelerations of their proper motions. Mathematical relations betweenthe astrometric observables Δμ, μ˙, and μ̈ andthe orbital elements are derived in the appendices. We find a remarkabledifference between the distribution of spectral types of stars withlarge accelerations but small proper motion differences and that ofstars with large proper motion differences but insignificantaccelerations. The spectral type distribution for the former sample ofbinaries is the same as the general distribution of all stars in theHipparcos catalog, whereas the latter sample is clearly dominated bysolar-type stars, with an obvious dearth of blue stars. We point outthat the latter set includes mostly binaries with long periods (longerthan about 6 yr).
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A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars
Rotational velocity vsin i and mean radial velocity are presented for asample of 231 Ib supergiant stars covering the spectral region F, G andK. This work is the second part of the large survey carried out with theCORAVEL spectrometer to establish the behavior of the rotation for starsevolving off the main sequence (De Medeiros & Mayor 1999). Thesedata will add constraints to the study of the rotational behavior inevolved stars, as well as solid information concerning tidalinteractions in binary systems and on the link between rotation,chemical abundance and activity in stars of intermediate masses. Basedon observations collected at the Haute-Provence Observatory,Saint-Michel, France and at the European Southern Observatory, La Silla,Chile Table 1 is 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/395/97
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Speckle Interferometry of New and Problem Hipparcos Binaries. II. Observations Obtained in 1998-1999 from McDonald Observatory
The Hipparcos satellite made measurements of over 9734 known doublestars, 3406 new double stars, and 11,687 unresolved but possible doublestars. The high angular resolution afforded by speckle interferometrymakes it an efficient means to confirm these systems from the ground,which were first discovered from space. Because of its coverage of adifferent region of angular separation-magnitude difference(ρ-Δm) space, speckle interferometry also holds promise toascertain the duplicity of the unresolved Hipparcos ``problem'' stars.Presented are observations of 116 new Hipparcos double stars and 469Hipparcos ``problem stars,'' as well as 238 measures of other doublestars and 246 other high-quality nondetections. Included in these areobservations of double stars listed in the Tycho-2 Catalogue andpossible grid stars for the Space Interferometry Mission.
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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
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Excitation and visibility of high-degree modes in stars
Observational evidence for excitation of non-radial modes in stars isconfronted with the results of linear stability surveys for stellarmodels. We consider various types of pulsators on the upper mainsequence as well as stars in the Cepheid strip. Our stability surveycovers the whole range of spherical harmonic degrees, l, whereinstability is found. There is fair agreement between the theoreticalinstability strip and the location of ζ Oph stars, but the observedand calculated periods do not agree in some stars. We suggest thateither pulsation is not responsible for the ζ Oph phenomenon orelse there are serious errors in mode identification in these cases. Wedo not find instability at long periods for early B-type stars,supporting the idea that pulsation is not responsible for the periodicvariations in Be stars. The agreement between the observed andcalculated periods of high-degree modes in δ Sct stars is not verysatisfactory. This is attributed to problems in mode identification. Wediscuss unstable modes of high degree in Cepheid models as a possiblemechanism for the low-amplitude radial velocities seen in some starswithin the instability strip. We find, however, that the observedperiods are at least a factor of 2 longer than the calculated periods.Finally, we discuss the possibility of observing modes of high degreephotometrically. We suggest that a large number of high-degree modes maybecome detectable by future space-borne photometric missions. Theconfusion arising from these modes may greatly reduce the value of suchobservations for asteroseismology. However, they will be very importantin studying the mechanism of mode selection.
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Absolute declinations with the photoelectric astrolabe at Calern Observatory (OCA)
A regular observational programme with a photoelectric astrolabe havebeen performed at ``Observatoire du Calern" (Observatoire de laCôte d'Azur, OCA, phi = +43() o44′55.011″; lambda =-0() h27() m42.44() s, Calern, Caussols, France) for the last twentyyears. It has been almost fully automatized between 1984 and 1987. Since1988 the photoelectric astrolabe was used without any modification. Inaddition to determining the daily orientation of the local vertical, theyearly analysis of the residuals permits to derive corrections to theused star catalogue \cite[(Vigouroux et al. 1992)]{vig92}. A globalreduction method was applied for the ASPHO observations. The new form ofthe equations \cite[(Martin & Leister 1997)]{mar97} give us thepossibility of using the entire set of the observing program using datataken at two zenith distances (30() o and 45() o). The program containsabout 41648 stars' transits of 269 different stars taken at``Observatoire du Calern" (OCA). The reduction was based on theHIPPARCOS system. We discuss the possibility of computing absolutedeclinations through stars belonging simultaneously to the 30() o and45() o zenith distances programmes. The absolute declination correctionswere determined for 185 stars with precision of 0.027arcsec and thevalue of the determined equator correction is -0.018arcsec +/-0.005arcsec . The instrumental effects were also determined. The meanepoch is 1995.29. Catalogue only available at CDS in electronic from viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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A Precision Velocity Study of Photometrically Stable Stars in the Cepheid Instability Strip
Results of a precision Doppler velocity survey of 15 stars that lie inor near the Cepheid instability strip are presented. Previous studieshave shown that these stars are photometrically stable. Long-term radialvelocity precision of 15 m s-1 has been achieved with the use of aniodine absorption cell and a high-resolution cross-dispersed echellespectrometer. The stars show a variety of behavior from stability (atthe level of 30 m s-1) to variability from 50 m s-1 to a few km s-1.Periodograms of many of the program stars show significant peaks at50-80 days that are not associated with radial pulsation. Previouslyundetected binary companions have been found around two of the stars.Line profiles are compared to delta Cep.
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BA II lines as luminosity indicators: s-Cepheids and non-variable supergiants
Ba II line equivalent widths appear to be well correlated with theabsolute magnitudes for yellow supergiants. Two Ba II lines 5853.6Angstroms and 6141.7 Angstroms were applied for investigation of thepossible relation between their equivalent widths and Mv forsmall-amplitude Cepheids and non-variable supergiants.
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Temperatures for A0-K0 Supergiants from 13-Color Photometry
Observations on the 13-color photometric system are reported for 71A0-K0 supergiant stars brighter than V=6.0. Three independent methods todetermine the effective temperatures for A0-K0 supergiants from their13C photometry are discussed: 1) Calibrations between T$eff$and reddening-free indices are developed; temperatures were collectedfrom the literature for the calibration stars, and most of them werespectroscopically determined. 2) An empirical correlation betweenintrinsic colors in the 13C system and T$eff$ has beenderived. 3) The unreddened colors are compared with synthetic colorscalculated by Kurucz (1989); this leads to simultaneous estimates forT$eff$ and log $g$. The estimated uncertainties inT$eff$ by the three methods are comparable and areapproximately plus or minus 200-300K. (SECTION: Stars)
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The Comparable Analysis of the Cepheids and Non-Variable Supergiants from the Instability STRIP.I.
Not Available
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A uvbyβ photometric calibration of iron abundances in supergiant stars.
A photometric reddening-free calibration for [Fe/H] valid for giant andsupergiant stars of intermediate temperature, has been obtained usingthe Stroemgren uvbyβ system. Galactic supergiants, supergiants inthe Magellanic Clouds and Galactic metal deficient red giants withspectroscopic determinations of [Fe/H] were used as calibrators. Thecalibration can be used to predict [Fe/H] with an accuracy of 0.33 dex,valid for stars with 0.14<[m_1_]<0.70 in the iron abundance range-2.5<[Fe/H]<+0.3. This shows the potential of supergiant stars astracers of iron abundances in other galaxies. Evidence that Galacticluminous F-G stars are intrinsically bluer than their counterparts inthe Magellanic Clouds is offered.
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Colour excesses of F-G supergiants and Cepheids from Geneva photometry.
A reddening scale for F-G supergiants and Cepheids is presented.Supergiants with low reddenings or in clusters form the basis of thecalibration. In this sense, it is entirely empirical. The data have beenobtained in the Geneva photometric system. Comparisons with otherreddening scales show no disagreement. The only problem is with Fernie'sscale for Cepheids (1990), where a systematic trend exists. Its originis not clear. It is suggested to extend the number of supergiants withindependently obtained colour excesses in order to test the existence ofa possible luminosity dependence of the calibration. A period-colourrelation for Cepheids is deduced, on the basis of the present reddeningcorrections. It gives strong support for V473 Lyr being a secondovertone pulsator.
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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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Calibrations of Mv, (Fe/H), and log G for yellow supergiant stars from O I 7774 and uvby-beta data
New calibrations of the absolute magnitude Mv from O I 7774data are derived from narrow-band photometry and low dispersionspectroscopy for AO-G2 low and high luminosity stars. The nonlineardependence of Mv from the equivalent width W(OI) and therelevance of the stellar temperature in the calibration are confirmed inagreement with previous calibrations obtained from high resolutionspectroscopy. Also functional formulas to estimate (Fe/H) and log g fromuvby-beta data for FO-G3 supergiants are offered. These calibrationspredict iron abundances and gravities for yellow supergiants withuncertainties not much higher than good spectroscopic determinations.
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An uvby-beta catalogue of F0-K0 supergiant stars brighter than V = 6.5
Photoelectric uvby-beta photometry is reported for 111 F0-K0 supergiantstars which are brighter than V = 6.5 mag and located betweendeclination of -15 and +61 deg. A comparison with previous observationsis made. A few stars which are suspected to present light variations arementioned.
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Groups of stars with common motion in the Galaxy - Groups of red supergiants of the luminosity classes I and II
Not Available
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Six centimetre VLA radio survey of compact planetary nebulae
The results are presented of a radio continuum survey of 174 objectsclassified as possible or true planetary nebulae (Acker et al, 1983).Intensity contour plots, radio flux densities at 5 GHz, diameters, andaccurate positions are presented for the detected objects. Many of thedetected sources have high radio surface brightness temperaturesindicative of young planetary nebulae. Also, for each of the programsources, the IRAS Point Source Catalog is used to extract the fourphotometric flux densities and derive the total infrared flux, a dusttemperature, and the infrared excess.
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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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Objective-prism discoveries in the northern sky. I
Attention is given to 175 northern hemisphere stars whose newlyrecognized peculiar, or otherwise prepossessing characteristics havebeen noted in a preliminary inspection of moderate dispersion objectiveprism plates. The plates were obtained with a 10-deg prism. The starlist gives HD or BD, alpha and delta values, magnitude, and type.
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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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Ultraviolet and optical studies of binaries with luminous cool primaries and hot companions. II - BVRI observations
Johnson system BVRI measurements are presented for 117 stars, most ofthem with no previous R and I photometry and many with no previous B andV. The prime objects for measurement are unresolved or nearly unresolvedbinaries containing a late-type giant or supergiant and an early-typecompanion. Other objects on the program include suspected binaries andother F-G giants and supergiants lacking at least R and I magnitudes.The variable F and G supergiants 1 Mon, 89 Her, HR 7308, HR 8157, HR8752, and rho-Cas and the eclipsing systems W Ser and ST Aqr wereobserved; HR 8752 showed significant dimming and cooling over 125 days.Several of Halliwell's (1979) candidates for nearby stars were measured.
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On the Existence of Stable Stars in the Cepheid Instability Strip
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJ...168..437F&db_key=AST
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The intensity of ScI (6305 A) in late stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970MNRAS.147..303G&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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Polarimetric Observations of Nearby Stars in the Directions of the Galactic Poles and the Galactic Plane
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968ApJ...151..907A&db_key=AST
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UBV photometry of 550 F, G and K type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966MNRAS.133..475A&db_key=AST
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Photoelectric measurements of the λ4200 A CN band and the G band in G8-K5 spectra
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960MNRAS.120..287G&db_key=AST
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Spectral Classification of Stars Noted on Case Objective-Prism Plates. I
Not Available
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A Finding List of F Stars of High Luminosity.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1952ApJ...115..475N&db_key=AST
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INHABITED SKY
