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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
| uvby photometry of the CP stars HR 149, HD 32966, HD 171782, and HR 7911
Differential Strömgren uvby observations from the Four CollegeAutomated Photoelectric Telescope (FCAPT) are presented for the CP starsHR 149 and HR 7911 and the mCP stars HD 32966 and HD 171782. TheMercury-Manganese star HR 149 is found to be constant while HR 7911 witha period of 5.9617 days probably has a component which is a magnetic CPstar. Improved periods were derived for HD 32966 and HD 171782 of 3.0927and 4.4674 days, respectively. The former is a rather large amplitudemCP star. Both have at least one light curve different in shape from theothers observed. Tables 2, 3, 4 and 5 are only available in electronicform at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/390/1023
| Lightcurves of 10 Hygiea, 241 Germania and 509 Iolanda
The asteroids 10 Hygiea, 241 Germania and 509 Iolanda have been studiedphotometrically. From their lightcurves, synodic periods of 27.63 +/-0.02, 15.51 +/- 0.01 and 12.72 +/- 0.02 hours, and amplitudes of 0fm 28,0fm 17 and 0fm 45, have been deduced for 10 Hygiea, 241 Germania and 509Iolanda, respectively. The period found for 241 Germania is asignificant revision from one previously published, and we present afirst indication of pole orientation and shape. A synodic period isobtained for 509 Iolanda. The solution obtained for the sense ofrotation, sidereal period, pole orientation and shape properties for 10Hygiea confirms previous results.
| Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
| On the HIPPARCOS photometry of chemically peculiar B, A, and F stars
The Hipparcos photometry of the Chemically Peculiar main sequence B, A,and F stars is examined for variability. Some non-magnetic CP stars,Mercury-Manganese and metallic-line stars, which according to canonicalwisdom should not be variable, may be variable and are identified forfurther study. Some potentially important magnetic CP stars are noted.Tables 1, 2, and 3 are available only in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Extreme amplitude variations in 28 And
New simultaneous observations using the four uvby filters of theStroemgren photometric system have been collected in the year 1996 forthe low amplitude delta Sct star 28 And. During the course of theseobservations, the observed amplitude of the light curves is very smallas compared with any other data set available in the literature for thisstar. In particular, the actual amplitude is about 19 times less thanduring the last observing run, five years before. The frequency analysisof the data also reveals the existence of a secondary frequency nu _2.Hence, the monoperiodicity is not confirmed with the new data. Inaddition, the analysis of the phase shifts between observed lightvariations confirms the nonradial nature of the main pulsation of thisstar.
| Infrared photometry and spectroscopy of the supersoft X-ray source RX J0019.8+2156 (= QR And)
We present JHK photometry and spectroscopy of RX J0019.8+2156. Thespectrum appears to be dominated by the accretion disc to at least 2.4mu m, over any other source of emission. We find Paschen, Brackett andHe II lines strongly in emission, but no He I. There are satellite linesapproximately 850km s(-1) either side of the strongest, unblendedhydrogen lines. These satellite lines may be the spectral signature ofjets from the accretion disc.
| 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.
| UBV photometry of stars whose positions are accurately known. VI
Results are presented from UBV photometric observations of 1000 stars ofthe Bright Star Catalogue and the faint extension of the FK5.Observations were carried out between July 1987 and December 1990 withthe 40-cm Cassegrain telescope of the Kvistaberg Observatory.
| Photoelectric photometry of chemically peculiar stars at the Catania Astrophysical Observatory. II - Observations of the CP3 stars HD 3322, HD 27295 and HD 89822
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1991A&A...244..327C&db_key=AST
| Theoretical characteristics of WR + O binaries
Using two kinds of stellar evolution models, one with convective coresdetermined by means of the Schwarzschild criterion, and the other withconvective cores enlarged by overshooting, the possible masses of theWR-stars in a number of double-lined WR binaries are discussed. It isshown that the virtual absence of observed main-sequence B-typecompanions in WR systems may, for mass-transfer dominated evolution, beexplained as a result of accretion effects on the inner structure of thecompanion star (rejuvenation) and, for wind mass-loss dominatedevolution, as a result of the large difference in luminosity between theWR star and its companion. Finally, investigating the formation processof the WR-stars in WR + O binaries, it is found that some of thesesystems must have been formed through mass exchange between thecomponents. Especially this is expected to be the case for the WRbinaries in the Small Magellanic Cloud.
| The Sirius supercluster
Photometric data on the chemical composition of 927 A stars in the UrsaMajor stream, called the Sirius supercluster, were used to estimate theage and place of formation of the objects. The stars studied are in thesolar neighborhood and have been observed to be co-moving in a velocityellipsoid with a (U, V) velocity of 10.3 km/sec and concentrated in aspatial volume less than 10 pc across. The Stromgren and Geneva systemphotometric data show that the supercluster is homogeneous in chemicalcontent, although the value of the forbidden Fe/H ratio could not beprecisely determined. The supercluster age is projected to be from260-620 Myr, with the origin having been in the Carina spiral arm of theGalaxy.
| The Postdam compilation of data on photometric variability of AP magnetic stars.
Not Available
| The A0 stars
A photometric grid, standardized on MK spectral standards, has been usedto compare spectral types and luminosity classes obtainedphotometrically with those in two extensive spectral surveys coveringthe entire sky. Major discrepancies include the spectroscopicclassification of B9.5, which may indicate an otherwise unrecognizedspectral peculiarity, a different A0/A1 spectral type boundary in thetwo samples involved, the well-known misclassification of weak heliumstars, and an appreciable percentage of stars which are called dwarfsspectroscopically but are of higher photometric luminosity. The spacemotion vectors of these stars for which radial velocities are available,and excluding the minimum of 25 percent that are spectroscopic binarieswithout orbital elements, show structure in their distribution in the(U, V)-plane, with members of the Local Association and the Hyades andSirius superclusters forming obvious concentrations. The members of theLocal Association in the samples are mainly old (more than 200 millionyears) mode A stars, although a few much younger stars are included. Themembers of the Hyades and Sirius superclusters contain many bluestragglers, including several peculiar stars of the Hg, Mn, and Sivarieties.
| The intermediate and narrow band photoelectric studies of some delta Scuti stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1983RMxAA...5..261I&db_key=AST
| Luminosities and motions of AO to A2 stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972PASP...84..757E&db_key=AST
| 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
| Variability of the Metallic-Line Star 28 Andromedae
The metallic-line A-type star 28 And was found to be variable both inbrightness and radial velocity. The brightness in blue varies by O~.O5,and the radial velocity by 5 km/sec with a period of 102 minutes. Theminimum light occurs 0.12 P before the maximum radial velocity. Therelation of 28 And to ö Scuti variables is brieflydiscussed
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Pozíciós és asztrometriai adatok
| Csillagkép: | Androméda |
| Rektaszcenzió: | 00h32m34.50s |
| Deklináció: | +27°34'50.0" |
| Vizuális fényesség: | 6.67 |
| Távolság: | 274.725 parszek |
| RA sajátmozgás: | -4.3 |
| Dec sajátmozgás: | -9.1 |
| B-T magnitude: | 6.772 |
| V-T magnitude: | 6.681 |
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