|FAUST Observations of Ultraviolet Sources toward the Virgo Cluster|
We analyze three UV images covering a ~100 square degree field towardthe Virgo cluster, obtained by the FAUST space experiment. We detect 191sources to a signal-to-noise ratio of 4.4 and identify 94% of them. Mostsources have optical counterparts in existing catalogs, and about halfare identified as galaxies. Some sources with no listed counterpart wereobserved at the Wise Observatory. We present the results oflow-resolution visible spectrophotometry and discuss the foreground 101stellar sources and the 76 detected galaxies, both in the cluster and inthe foreground or background. We derive conclusions on star formationproperties of galaxies and on the total UV flux from discrete anddiffuse sources in the cluster. We test for the presence of intraclusterdust, determine the clustering properties of UV emitting galaxies, andderive the UV luminosity function of Virgo galaxies.
|Mesures et decouvertes d'etoiles doubles effectuees a la lunette de 50cm de l'Observatoire de Nice. Measures and discoveries of visual double stars made with the 50cm refractor at the Nice Observatory.|
Measures and discoveries of visual double stars made at the Observatoirede la Cote d'Azur at Nice, between 1988 and 1994, with the 50cmrefractor equipped with a filar micrometer and electronic recordingdevice. The programs proposed by J. Dommanget involve the complement ofthe C.C.D.M. (resolving problems of identification of double stars andof coherency in the Index) and the INput CAtalog Hipparcos (resolutionof ambiguities on the binarity and on the position of certain doublestars which have seldom or never been observed again from the epoch ortheir discovery). The author has discovered three new binaries: JCT1,JCT2 and JCT3.
|A catalog of far-ultraviolet point sources detected with the fast FAUST Telescope on ATLAS-1|
We list the photometric measurements of point sources made by the FarUltraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 spaceshuttle mission. The list contains 4698 Galactic and extragalacticobjects detected in 22 wide-field images of the sky. At the locationssurveyed, this catalog reaches a limiting magnitude approximately afactor of 10 fainter than the previous UV all-sky survey, TDl. Thecatalog limit is approximately 1 x 10-14 ergs A sq cm/s,although it is not complete to this level. We list for each object theposition, FUV flux, the error in flux, and where possible anidentification from catalogs of nearby stars and galaxies. Thesecatalogs include the Michigan HD (MHD) and HD, SAO, the HIPPARCOS InputCatalog, the Position and Proper Motion Catalog, the TD1 Catalog, theMcCook and Sion Catalog of white dwarfs, and the RC3 Catalog ofGalaxies. We identify 2239 FAUST sources with objects in the stellarcatalogs and 172 with galaxies in the RC3 catalog. We estimate thenumber of sources with incorrect identifications to be less than 2%.
|Reality Tests of Superclusters in the Young Disk Population|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995AJ....110.2862E&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.
|NGC 4526 gas, high velocity clouds, and Galactic halo gas: the interstellar medium towards SN 1994D.|
We present spectroscopic observations of supernova 1994D in NGC 4526, anS0_3_ galaxy in the Virgo cluster 15Mpc distant. The datasets consist ofthe interstellar Ca II and Na I lines towards the supernova at highspectral resolution (FWHM 6km/s), H α and [N II] observations atlower resolution (FWHM 33km/s) of the nucleus of NGC 4526 and thesupernova, obtained with the William Herschel Telescope at La Palma, and21cm spectra obtained with the 100m Effelsberg Radiotelescope in thefield of NGC 4526. The velocity of the gas in NGC 4526 determined fromour H α spectra is +625km/s at the centre (systemic velocity) and+880km/s at the supernova position. Our value of the systemic velocityis higher than the value of +450km/s frequently quoted in theliterature. In our high resolution spectra we detect Ca II and Na Iabsorption at +714km/s which is produced in interstellar gas in NGC4526. To our knowledge this is the first detection of interstellarabsorption originating in a galaxy of early morphological type. Theratio N(Na^0^)/N(Ca^+^)=~4 suggests an origin in cold gas at restvelocity relative to its galactic environment. The lack of multiplecomponents indicates a relatively simple structure of the interstellarmedium in the inner region of NGC 4526, at least in the particular lineof sight to the supernova at the border of the nuclear ring of dust. Wedetect multi-component Ca II and Na I absorption lines in the range from+204 to +254km/s which originate in a complex of High Velocity Clouds(HVCs) located at a distance <<1Mpc, in the surroundings of theMilky Way. This rare detection of HVCs in absorption enables the studyof the properties of the gas using the Ca^+^ and Na^0^ column densities,combined with the H^0^ column density taken from the literature at+215km/s in the same line of sight. We find N(Na^0^)/N(Ca^+^)=0.1-0.3,in our Galaxy the signature of high velocity gas. The Ca^+^/H^0^ andNa^0^/H^0^ column density ratios are extremely high compared to MilkyWay interstellar values; the gas appears to have near solar abundances,very low dust content, and a diluted ultraviolet radiation field. Thisis entirely consistent with Galactic fountain models, in which hot gasis expelled into the outer halo, and subsequently cools. At -29km/s, wefind weak Ca II absorption and weak H I emission. This component hasproperties similar to those of the warm gas around the Sun and mayoriginate in gas infalling onto the Galactic disk, perhaps associatedwith the extended complexes of Galactic halo gas at intermediatenegative velocities which are present in the northern Galactichemisphere. Finally, close to rest velocity, we find both warm and coldgas located beyond 65pc, probably associated with high latitude gas atthe border of Loop I. The total reddening of the supernova, estimatedusing the standard Milky Way gas-to-dust ratio, is E(B-V)=~0.05.
|The southern Vilnius photometric system. I - Transformation to the standard system|
This paper is the first in a series on the extension of the Vilniusphotometric system to the southern hemisphere. Observations of a commonset of 73 stars measured in both hemispheres are described and ananalysis of the differences is given.
|The kinematics of young disk population supercluster members|
A discussion of the total space motions of early-type members of youngdisk population superclusters, derived from distances based on aphotometric calibration of four-color and H-beta photometry, shows anincrease in total velocity with increasing radial distance from the sun,within each supercluster. The rate of increase with distance varies fromsupercluster to supercluster because it results from the interaction oftwo effects - an 'expansion' that involves the total space motion and a'rotation' that involves only the V-velocity because it arises from therequirement that supercluster members have isoperiodic, galactic orbits.The ratio of the velocity in the direction of galactic rotation(V-velocity) to the total space motion determines the size of theresultant effect from the contradictory 'rotation' and 'expansion'terms. The expansion term is 40 to 45 km's/kpc in the superclustersdiscussed, whereas the rotation term is dV/dX = -(b-A) = 26 km/s/kpc,where B and A are the constants of galactic rotation.
|The IC 2391 supercluster|
Sixty-three field stars and the sparse cluster IC 2391 have beenidentified as members of the IC 2391 supercluster. The members have atleast 95 percent of their space motion, directed toward (A,D) = (5.82h,- 12.44d). Like members of the very similar Pleiades supercluster, theIC 2391 supercluster contains objects of two ages: t = 8 x 19 exp 7 and2.5 x 10 exp 8 yr. A prototype very active chromosphere star and theenigmatic giant variable TZ For are supercluster members together withtwo A-type stars suspected of possessing particulate disks. Anespecially interesting member is the system of Xi Cep (HR 8417) in whichthe two brightest components are greatly undermassive.
|Observations of double stars and new pairs. XIV|
Results of a continuing survey of visual double stars are presented,including 4880 measurements made from February 1987 to November 1989.The positions in WDS format and Durchmusterung numbers are given for 194pairs first reported here. Micrometer measurements of 1142 doubles madewith the Swarthmore 61 cm refractor are presented. Magnitudes areestimated for some of the objects. Plate measurements, plateorientations, position angles, number of nights, and measured exposuresare given. Visual observations of 342 pairs obtained in May 1989 atCerro Tololo, mostly with the 1.0 m reflector, are reported.
|Catalogue of the energy distribution data in spectra of stars in the uniform spectrophotometric system.|
|Energy Distribution Data in the Spectra of 72 Stars in the Region Lambda 3200A to 7600A|
|The Delta Scuti Variable GG Vir|
|Rho Vir: a Hot Delta Scuti Star?|
|Prediction of spectral classification from photometric observations - Application of the UVBY beta photometry and the MK spectra classification. II - General case|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&A....85...93M&db_key=AST
|Prediction of spectral classification from photometric observations-application to the UVBY beta photometry and the MK spectral classification. I - Prediction assuming a luminosity class|
An algorithm based on multiple stepwise and isotonic regressions isdeveloped for the prediction of spectral classification from photometricdata. The prediction assumes a luminosity class with reference touvbybeta photometry and the MK spectral classification. The precisionattained is about 90 percent and 80 percent probability of being withinone spectral subtype respectively for luminosity groups I and V and forluminosity groups III and IV. A list of stars for which discrepanciesappear between photometry and spectral classification is given.
|Spectral classification from the ultraviolet line features of S2/68 spectra. III - Early A-type stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...33...15C&db_key=AST
|27 Vir: a possible delta Scuti star|
|Catalogue of early-type stars measured in a narrow-band photometric system|
A compilation of the photoelectric measurements in the Barbier-Morguleffsystem is presented. The catalogue includes data for 773 stars ofspectral type 08 to F6. 706 stars have been measured at least twice.
|Four-color and Hβ photometry for the brighter AO type stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972A&AS....5..109C&db_key=AST
|A catalogue of proper motions for 437 A stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970A&AS....1..189F&db_key=AST
|Photoelectric observations of early A stars|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970A&AS....1..165J&db_key=AST
|Micrometer Measures of Double Stars.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJS....6....1K&db_key=AST
|Observation of Occultations at Skalnaté Pleso Observatory During the Years 1950-1953|
|Observations of Occultations in the Years 1953 and 1954|
|Spectroscopic magnitudes of A-type stars.|