Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i
This work is the second part of the set of measurements of v sin i forA-type stars, begun by Royer et al. (\cite{Ror_02a}). Spectra of 249 B8to F2-type stars brighter than V=7 have been collected at Observatoirede Haute-Provence (OHP). Fourier transforms of several line profiles inthe range 4200-4600 Å are used to derive v sin i from thefrequency of the first zero. Statistical analysis of the sampleindicates that measurement error mainly depends on v sin i and thisrelative error of the rotational velocity is found to be about 5% onaverage. The systematic shift with respect to standard values fromSlettebak et al. (\cite{Slk_75}), previously found in the first paper,is here confirmed. Comparisons with data from the literature agree withour findings: v sin i values from Slettebak et al. are underestimatedand the relation between both scales follows a linear law ensuremath vsin inew = 1.03 v sin iold+7.7. Finally, thesedata are combined with those from the previous paper (Royer et al.\cite{Ror_02a}), together with the catalogue of Abt & Morrell(\cite{AbtMol95}). The resulting sample includes some 2150 stars withhomogenized rotational velocities. Based on observations made atObservatoire de Haute Provence (CNRS), France. Tables \ref{results} and\ref{merging} are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/393/897
|
Research Note Hipparcos photometry: The least variable stars
The data known as the Hipparcos Photometry obtained with the Hipparcossatellite have been investigated to find those stars which are leastvariable. Such stars are excellent candidates to serve as standards forphotometric systems. Their spectral types suggest in which parts of theHR diagrams stars are most constant. In some cases these values stronglyindicate that previous ground based studies claiming photometricvariability are incorrect or that the level of stellar activity haschanged. Table 2 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/367/297
|
Shock Excitation in Interacting Galaxies: Markarian 266
We present near-infrared data on the luminous interacting system Mrk 266(NGC 5256), comprising 2 μm continuum, and Brγ and 1-0 S(1)emission-line images, together with K-band spectra. We have fittedstellar templates to the continuum, allowing us to account for all thestellar features and hence detect even faint gas excitation emissionlines, including eight and 11 H2 lines in the southwest andnortheast nuclei, respectively. Population diagrams for the excitedH2 molecules indicate that most of the 1-0 S(1) in each ofthe nuclei has a thermal origin. We discuss this with reference to theobserved morphologies, especially that of the 1-0 S(1) line. Inparticular, the core of 1-0 S(1) in the northeast nucleus is morecompact than the 2 μm continuum, while in the southwest nucleus the1-0 S(1) is significantly offset by 500 pc from the continuum (andother) emission. Last, we address the issue of the region midway betweenthe two nuclei, where previously a strong source of radio continuum hasbeen observed. These results are set in the context of interactinggalaxies where shock-excited emission might be expected to occur as adirect consequence of the interaction.
|
A Second Catalog of Orbiting Astronomical Observatory 2 Filter Photometry: Ultraviolet Photometry of 614 Stars
Ultraviolet photometry from the Wisconsin Experiment Package on theOrbiting Astronomical Observatory 2 (OAO 2) is presented for 614 stars.Previously unpublished magnitudes from 12 filter bandpasses withwavelengths ranging from 1330 to 4250 Å have been placed on thewhite dwarf model atmosphere absolute flux scale. The fluxes wereconverted to magnitudes using V=0 for F(V)=3.46x10^-9 ergs cm^-2 s^-1Å^-1, or m_lambda=-2.5logF_lambda-21.15. This second catalogeffectively doubles the amount of OAO 2 photometry available in theliterature and includes many objects too bright to be observed withmodern space observatories.
|
Mesures de vitesses radiales. VIII. Accompagnement AU sol DU programme d'observation DU satellite HIPPARCOS
We publish 1879 radial velocities of stars distributed in 105 fields of4^{\circ} \times 4^{\circ}. We continue the PPO series \cite[(Fehrenbachet al. 1987;]{Feh87} \cite[Duflot et al. 1990, 1992 and 1995),]{Du90}using the Fehrenbach objective prism method. Table 1 only available inelectronic form at CDS via to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
|
Intrinsic Energy Distribution in Stellar Spectra in the Wavelength Interval 320--760 NM
The intrinsic energy distributions in the interval 320--760 nm ofspectral types B5--G8 of luminosity V, F0--F5 of luminosity IV andG8--M2 of luminosity III, determined by authors, are intercompared withthe catalogue of the mean energy distribution data published bySviderskiene (1988).
|
The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJS...99..135A&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.
|
APT Observations of Small-Amplitude Red Variables
Not Available
|
Third preliminary catalogue of stars observed with the photoelectric astrolabe of the Beijing Astronomical Observatory.
Not Available
|
Starbursts, binary stars, and blue stragglers in local superclusters and groups. I - The very young disk and young disk populations
The distributions in the HR diagram with theoretical time-constant locifor stars in several young clusters and superclusters are compared todemonstrate that 'blue stragglers' in these aggregates are mostfrequently simply single massive (mode B) stars formed in bursts of starformation that occur at discrete intervals in time following theformation of the bulk of the low-mass (mode A) stars in the aggregate.The characteristics of the close binary systems in these aggregates areexamined to show that, in several cases, mass transfer by Roche lobeoverflow has or will occur and that, in some instances, the system wouldhave appeared as a blue straggler prior to the mass-transfer event, and,in other instances, mass transfer will lead to the identification of thesystem as a blue straggler. Thus, it is concluded that the bluestraggler phenomenon has at least two distinct physical origins: it mayoriginate from delayed formation (starbursts) or from 'delayedevolution' in some close binaries (mass transfer from an evolvedprimary).
|
The Hyades moving group - New members, kinematics, age
Thirteen candidate members of the Hyades moving group have beenidentified by a statistical kinematic criterion from among 927 A-typefield stars whose space velocities are known. Several arguments supporta genetic relationship between these objects and the Hyades'supercluster') their kinematic parameters are close to those of thesupercluster; and (2) the members have similar or equal ages whose meanvalue, (6.3 + or - 0.6) x 10 to the 8th yr, is consistent with the ageof the Hyades open cluster and the kinematic-age estimate for the Hyadesmoving group.
|
A systematic search for members of the Hyades Supercluster. IV - The metallic-line stars and ultrashort-period Cepheids
Bright Star Catalog stars with beta values in the 2.70-2.88 rangecontain 127 members of the Hyades Supercluster, which have been chosenon the basis of the direction of their proper motion. Available radialvelocities confirm supercluster membership for most of these stars.Exceptional regularity is noted in the values of the pulsation constantQ computed for the ultrashort period Cepheids on the basis of knownperiods, model masses and model radii. Outside the center of the Hyadescluster, the largest concentration of supercluster stars is in a regionof 30 pc radius, between 60 and 80 pc above the sun, where 30 percent ofthe expected stars in the temperature range presently discussed aresupercluster members.
|
Photometric UBV period study of eight AP stars
Eight Ap stars for which periods had been determined by Winzer (1974)were the subject of an independent period determination. All were starswhich were found to be short-period variables and which showed thetypical small-amplitude variation associated with short periods. For sixof these, the period was confirmed. For one, HR 9017, a different andbetter period was determined and for the remaining star, HR 4430,periodic variation was not observed.
|
Absolute luminosity calibration of Stroemgren's 'late group'
A statistical parallax method based on the principle of maximumlikelihood is used to calibrate absolute luminosities for samples ofcooler stars constituting the 'late group' defined by Stromgren (1966).The samples examined include 415 stars of all luminosity classes and asubset comprising 86 main-sequence stars. Linear calibration relationsinvolving the Stromgren beta, (b-y), and bracketted c1 indices arederived which yield mean absolute magnitudes with an accuracy of 0.09magnitude for the overall sample and 0.13 magnitude for themain-sequence subsample. Several second-order relations are considered,and the results are compared with Crawford's (1975) calibrations as wellas with mean absolute magnitudes obtained from trigonometric parallaxes.The possible effect of interstellar absorption on the calibrationrelations is also investigated.
|
Interstellar circular polarization. II - Northern and southern hemisphere survey results and observational search criteria
An original survey has been extended to include more northern andsouthern hemisphere stars; the wavelength coverage was extended and theprecision improved for several previously observed stars. Searchcriteria for interstellar circular polarization based on the linearpolarization and reddening have been delineated and refined.Observational data are presented which confirm the theoreticalprediction that the wavelength of maximum interstellar linearpolarization and the wavelength of the zero crossing of interstellarcircular polarization are approximately the same. An intercomparison ofthe results of various authors is presented and briefly discussed.
|
Über die Veränderlichkeit der Sterne des Spektraltyps A
Not Available
|
K-Line Photometry of Southern a Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJS...23..421H&db_key=AST
|
K-Line Photometry of a Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969ApJS...18...47H&db_key=AST
|
Catalogue des étoiles mesurées dans le système photométrique de l'Observatoire de Genève
Not Available
|
Spectroscopic magnitudes of A-type stars.
Not Available
|
