|New periodic variables from the Hipparcos epoch photometry|
Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.
|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 (18.104.22.168) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcar?J/A+A/367/521
|The proper motions of fundamental stars. I. 1535 stars from the Basic FK5|
A direct combination of the positions given in the HIPPARCOS cataloguewith astrometric ground-based catalogues having epochs later than 1939allows us to obtain new proper motions for the 1535 stars of the BasicFK5. The results are presented as the catalogue Proper Motions ofFundamental Stars (PMFS), Part I. The median precision of the propermotions is 0.5 mas/year for mu alpha cos delta and 0.7mas/year for mu delta . The non-linear motions of thephotocentres of a few hundred astrometric binaries are separated intotheir linear and elliptic motions. Since the PMFS proper motions do notinclude the information given by the proper motions from othercatalogues (HIPPARCOS, FK5, FK6, etc.) this catalogue can be used as anindependent source of the proper motions of the fundamental stars.Catalogue (Table 3) is only available at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (22.214.171.124) or viahttp://cdsweb.u-strastg.fr/cgi-bin/qcat?J/A+A/365/222
|Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions|
The FK6 is a suitable combination of the results of the HIPPARCOSastrometry satellite with ground-based data, measured over more than twocenturies and summarized in the FK5. Part I of the FK6 (abbreviatedFK6(I)) contains 878 basic fundamental stars with direct solutions. Suchdirect solutions are appropriate for single stars or for objects whichcan be treated like single stars. From the 878 stars in Part I, we haveselected 340 objects as "astrometrically excellent stars", since theirinstantaneous proper motions and mean (time-averaged) ones do not differsignificantly. Hence most of the astrometrically excellent stars arewell-behaving "single-star candidates" with good astrometric data. Thesestars are most suited for high-precision astrometry. On the other hand,199 of the stars in Part I are Δμ binaries in the sense ofWielen et al. (1999). Many of them are newly discovered probablebinaries with no other hitherto known indication of binarity. The FK6gives, besides the classical "single-star mode" solutions (SI mode),other solutions which take into account the fact that hidden astrometricbinaries among "apparently single-stars" introduce sizable "cosmicerrors" into the quasi-instantaneously measured HIPPARCOS proper motionsand positions. The FK6 gives in addition to the SI mode the "long-termprediction (LTP) mode" and the "short-term prediction (STP) mode". TheseLTP and STP modes are on average the most precise solutions forapparently single stars, depending on the epoch difference with respectto the HIPPARCOS epoch of about 1991. The typical mean error of anFK6(I) proper motion in the single-star mode is 0.35 mas/year. This isabout a factor of two better than the typical HIPPARCOS errors for thesestars of 0.67 mas/year. In the long-term prediction mode, in whichcosmic errors are taken into account, the FK6(I) proper motions have atypical mean error of 0.50 mas/year, which is by a factor of more than 4better than the corresponding error for the HIPPARCOS values of 2.21mas/year (cosmic errors included).
|The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle|
The sixth annual catalog of the Tokyo Photoelectric Meridian Circle(PMC) is presented for 6649 stars which were observed at least two timesin January 1990 through March 1993. The mean positions of the starsobserved are given in the catalog at the corresponding mean epochs ofobservations of individual stars. The coordinates of the catalog arebased on the FK5 system, and referred to the equinox and equator ofJ2000.0. The mean local deviations of the observed positions from theFK5 catalog positions are constructed for the basic FK5 stars to comparewith those of the Tokyo PMC Catalog 89 and preliminary Hipparcos resultsof H30.
|Systematic Errors in the FK5 Catalog as Derived from CCD Observations in the Extragalactic Reference Frame.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114..850S&db_key=AST
|The ROSAT all-sky survey catalogue of optically bright OB-type stars.|
For the detailed statistical analysis of the X-ray emission of hot starswe selected all stars of spectral type O and B listed in the Yale BrightStar Catalogue and searched for them in the ROSAT All-Sky Survey. Inthis paper we describe the selection and preparation of the data andpresent a compilation of the derived X-ray data for a complete sample ofbright OB stars.
|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.
|Reliable photometric reductions to the standard UBV (or uvby) system and accurate UBV magnitudes of bright standard stars from the northern part of the international Be program|
A modified method of computer reduction of UBV (or uvby) photoelectricobservations to standard systems, which combines advantages of what hasso far been achieved in this area, is described in detail. A completereduction of over 46000 UBV observations obtained at Hvar Observatorybetween 1972 and 1991, and of nearly 5000 UBV observations secured atSkalnate Pleso Observatory between 1980 and 1987, was carried out usingthe new technique. It is argued that replacing the original Johnson'sUBV values for the non-variable stars that were observed by the meanvalues based on repeated observations over several years and applyingthe new reduction technique can ensure a stable reproduction of UBVmagnitudes, obviously quite close to the standard Johnson's ones, overmany years and from observatories situated at very different altitudesabove sea level within about 0.01mag in all three UBV magnitudes. A listof new accurate mean UBV values of 191 stars which were regularlyobserved at Hvar - and a part of them also at Skalnate Pleso - ascomparison, check and standard stars in the Be- and Ap-star observingprograms, is included for future use by photometric observers in theNorthern Hemisphere. For a number of these stars, we can guaranteesecular constancy within 0.mag01 during the past 5 to 15 years.
|Corrections to the right ascension to be applied to the apparent places of 1217 stars given in "The Chinese Astronomical Almanach" for the year 1984 to 1992.|
|An Einstein Observatory SAO-based catalog of B-type stars|
About 4000 X-ray images obtained with the Einstein Observatory are usedto measure the 0.16-4.0 keV emission from 1545 B-type SAO stars fallingin the about 10 percent of the sky surveyed with the IPC. Seventy-fourdetected X-ray sources with B-type stars are identified, and it isestimated that no more than 15 can be misidentified. Upper limits to theX-ray emission of the remaining stars are presented. In addition tosummarizing the X-ray measurements and giving other relevant opticaldata, the present extensive catalog discusses the reduction process andanalyzes selection effects associated with both SAO catalog completenessand IPC target selection procedures. It is concluded that X-rayemission, at the level of Lx not less than 10 exp 30 ergs/s, is quitecommon in B stars of early spectral types (B0-B3), regardless ofluminosity class, but that emission, at the same level, becomes lesscommon, or nonexistent, in later B-type stars.
|Santiago Fundamental Catalogue - A catalogue of 1105 FK5 stars (equinox J2000.0)|
The positions in right ascension and declination of 1105 FK5 stars,observed with a Meridian Circle during the period 1979 to 1991, aregiven. The average mean square error of a position, for the wholecatalog, is +/- 0.009 s in right ascension and +/- 0.10 arcsec indeclination. The mean epoch of the catalog is 1983.148.
|The correction in right ascension of 508 stars determinated with PMO photoelectric transit instrument.|
|Fourth preliminary catalogue of stars, right ascension observed with photoelectric transit instrument (PPCP4).|
|The EXOSAT high Galactic latitude survey|
This study presents a survey of serendipitous sources performed in thevery soft X-ray band (0.05-2.0 keV) using the Exosat imaging telescopes.It covers 783 sq deg of high Galactic latitude sky and includes 210serendipitous sources which define a complete (flux-limited) sample. Twohundred of the 210 detected sources are identified via extensive opticaland radio observations together with cross-correlations with catalogs ofknown objects. The log N-log S relation was found to be consistent withthat of the Einstein extended Medium-Sensitivity Survey (EMSS) and withthe 'Euclidean' value of 1.5. The normalization of the relation is astrong function of the assumed spectral slope of AGN. It is inferredfrom the consistency with the EMSS results that the average (energy)slope of extragalactic sources in the soft X-ray band is very steep(approximately 1.5). An analysis of the association between AGNdetection and Galactic N(H) also shows that the average slope is steepand inconsistent with the canonical value of 0.7.
|Physical data of the fundamental stars.|
|Catalogue of i and w/w crit values for rotating early type stars|
|Third preliminary catalogue of stars observed with the photoelectric astrolabe of the Beijing Astronomical Observatory.|
|Empirical temperature calibrations for early-type stars|
Three temperature calibrations of suitable photometric quantities havebeen derived for O and B stars. A sample of 120 stars with reliableT(eff.) determinations has been used for establishing each calibration.The different calibrations have been critically discussed and compared.Temperature determinations for 1009 program stars have been obtainedwith an accuracy of the order of 10 percent.
|Right ascension corrections to 120 FK 4-stars by the analysis of time observations obtained with the Photoelectric Transit Instrument at Torino Observatory|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1987A&A...183..403C&db_key=AST
|A catalog of ultraviolet interstellar extinction excesses for 1415 stars|
Ultraviolet interstellar extinction excesses are presented for 1415stars with spectral types B7 and earlier. The excesses with respect to Vare derived from Astronomical Netherlands Satellite (ANS) 5-channel UVphotometry at central wavelengths of approximately 1550, 1800, 2500, and3300 A. A measure of the excess extinction in the 2200-A extinction bumpis also given. The data are valuable for investigating the systematicsof peculiar interstellar extinction and for studying the character of UVinterstellar extinction in the general direction of stars for which theextinction-curve shape is unknown.
|The local system of early type stars - Spatial extent and kinematics|
Published uvby and H-beta photometric data and proper motions arecompiled and analyzed to characterize the structure and kinematics ofthe bright early-type O-A0 stars in the solar vicinity, with a focus onthe Gould belt. The selection and calibration techniques are explained,and the data are presented in extensive tables and graphs and discussedin detail. The Gould belt stars of age less than 20 Myr are shown togive belt inclination 19 deg to the Galactic plane and node-lineorientation in the direction of Galactic rotation, while the symmetricaldistribution about the Galactic plane and kinematic properties (purecircular differential rotation) of the belt stars over 60 Myr oldresemble those of fainter nonbelt stars of all ages. The unresolveddiscrepancy between the expansion observed in the youngest nearby starsand the predictions of simple models of expansion from a point isattributed to the inhomogeneous distribution of interstellar matter.
|Absorption Line Profiles for 39 Rapidly Rotating Stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1984MNRAS.208..459S&db_key=AST
|Be stars in binaries|
The known companions to 80 Be stars and 355 B stars listed in the BrightStar Catalogue in the range B1-B7 III-V and north of delta = -30 deg areconsidered. The known near-absence of Be binaries with periods less than1/10 yr is confirmed. For longer periods up to the limit of 10,000 AU ofthis survey, the Be and B stars do not differ in binary frequencies.This result implies that during pre-main-sequence contraction, the tidalbraking in binaries wider than 0.5 AU was inadequate to prevent theformation of stars with nearly the break-up rotational velocities. Thefraction of Be and B stars that have companions is higher in clustersand associations (38 percent) than among field stars (25 percent),confirming that escapees from clusters tend to be single stars. There issome evidence that the companions of Be stars that occur in the sameluminosity range tend also to be Be stars; that result was expectedbecause in visual binaries there is a known tendency for rapidlyrotating primaries to have rapidly rotating secondaries.
|The fourth meridian catalog of Besancon Observatory|
The catalog presented gives differential meridian positions for 670F-type stars between plus 15 and plus 45 deg declination. The positionsare reduced to the equinox of 1950.0 without proper motions; 333 FK4stars were used as reference stars. A minimum of three and an average offive transits of each program star were observed photoelectrically usinga Gautier transit circle and a Hog grid. The internal accuracy ofindividual measurements is shown to range from 0.013 sec in rightascension and 0.30 arcsec in declination for brighter stars under betterobserving conditions to 0.020 sec in right ascension and 0.38 arcsec indeclination for fainter stars under worse conditions. The standarderrors were applied to compute weighted mean positions, mean epochs, andunweighted means for the program stars. Mean corrections for 283 FK4stars are also provided.
|Narrow-band photometry of Beta Lyrae in 1971|
Observations of Beta Lyrae (with HR 6997 as the principal companionstar) are presented, principally of certain strong lines and neighboringcontinuum regions obtained through interference filters of bandwidthsranging from 27.0 to 33.7 A. Light curves in the 3 blue and 3 red bandsare shown, and color indices and emission intensity indices aretabulated. Moreover, a photometric index of emission line strength,analogous to the spectroscopic index of Batten and Sahade (1973), isderived. It is suggested that the H alpha emission comes from a largerregion around the binary star than does the helium emission and isasymmetrical, being weakest near quadrature when the primary star isapproaching earth. The helium emission, by contrast, is moresymmetrical, and varies with binary phase by a larger fractional amount.
|Coordinate improvements for FK4 stars from observations with the Ni2 astrolabe|
Individual coordinate improvements were derived for 241 FK4 stars from alarge number of astrogeodetic plumb-line deflection measurements. Thecorrections on the average amount to 0.2 arc sec, with extrema of 0.6arc sec. Half of the values are based on at least eight observations andare accurate to plus or minus 0.13 arc sec. Comparative studies showthat the results are free of systematic errors and that the mean errorsare reliable.
|Space velocities and ages of nearby early-type stars|
Photometric distances and space velocities have been calculated for 458B0-A0 stars with apparent magnitudes not exceeding 6.5. UsingStromgren's ubvy-beta photometry the effective temperature and theposition in bolometric magnitude over the zero-age main sequence of thestars were derived. These quantities were used to obtain age and massfor 423 of the stars by interpolation in the models of stellar evolutionfor the chemical composition (X Z) = (0.7, 0.03). A relation forderiving interstellar reddening for normal stars in the intermediategroup is given.
|Catalogue general des etoiles observees a l'astrolabe (1957-1975), corrections individuelles aux positions DU FK4.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...31..159B&db_key=AST
|Is star formation bimodal ? II. The nearest early-type stars.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977PASP...89..187E&db_key=AST