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Hot subdwarf stars in close-up view. II. Rotational properties of single and wide binary subdwarf B stars
Subluminous B stars (sdBs) form the extremely hot end of the horizontalbranch and are therefore related to the blue horizontal branch (BHB)stars. While the rotational properties of BHB stars have beeninvestigated extensively, studies of sdB stars have concentrated onclose binaries that are influenced by tidal interactions between theircomponents. Here we present a study of 105 sdB stars, which are eithersingle stars or in wide binaries where tidal effects become negligible.The projected rotational velocities have been determined by measuringthe broadening of metal lines using high-resolution optical spectra. Allstars in our sample are slow rotators (vrotsini < 10 kms-1). Furthermore, the vrotsini-distributions ofsingle sdBs are similar to those of hot subdwarfs in wide binaries withmain-sequence companions as well as close binary systems with unseencompanions and periods exceeding ?1.2 d. We show that bluehorizontal and extreme horizontal branch stars are also related in termsof surface rotation and angular momentum. Hot BHB stars (Teff> 11 500 K) with diffusion-dominated atmospheres are slow rotatorslike the hot subdwarf stars located on the extreme horizontal branch,which lost more envelope and therefore angular momentum in the red-giantphase. The uniform rotation distributions of single and wide binary sdBspose a challenge to our understanding of hot subdwarf formation.Especially the high fraction of helium white dwarf mergers predicted bytheory seems to be inconsistent with the results presented here.Based on observations at the Paranal Observatory of the EuropeanSouthern Observatory for programmes number 165.H-0588(A), 167.D-0407(A),071.D-0380(A) and 072.D-0487(A). Based on observations at the La SillaObservatory of the European Southern Observatory for programmes number073.D-0495(A), 074.B-0455(A), 076.D-0355(A), 077.D-0515(A) and078.D-0098(A). Based on observations collected at the CentroAstronómico Hispano Alemán (CAHA) at Calar Alto, operatedjointly by the Max-Planck Institut für Astronomie and the Institutode Astrofísica de Andalucía (CSIC). Some of the datapresented here were obtained at the W. M. Keck Observatory, which isoperated as a scientific partnership among the California Institute ofTechnology, the University of California, and the National Aeronauticsand Space Administration. The Observatory was made possible by thegenerous financial support of the W. M. Keck Foundation. Based on dataobtained with the Hobby-Eberly Telescope (HET), which is a joint projectof the University of Texas at Austin, the Pennsylvania State University,Stanford University, Ludwig-Maximilians-Universität München,and Georg-August-Universität Göttingen.
| Catalogue of Ap, HgMn and Am stars
We present a catalogue of 8205 known or suspected Ap, HgMn and Am stars.This paper is a major update of our first edition of the catalog of Apand Am stars and includes revised identifications, additional stars andrevised information obtained from the literature.Catalogue (full Table 1) is only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/498/961
| Revised and Updated Catalogue of the First Byurakan Survey Blue Stellar Objects
Eleven lists of blue stellar objects (BSOs) were published inAstrophysics in 1990-1996, found in the First Byurakan Survey (FBS)low-dispersion spectroscopic plates. The selection was carried out inthe region with +33° > ? > +45° and ? >+61° with a surface of 4000 deg2. As a result, thecatalogue of the FBS BSOs was compiled. Its preliminary version has beenavailable at Centre de Données Astronomiques de Strasbourg since1999. We revised and updated the FBS BSOs catalogue with new data fromrecently published optical and multiwavelength catalogs to give accessto all available data and make further comparative studies of theproperties of these objects possible. We made cross-correlations of theFBS BSOs catalogue with the Minnesota Automated Plate Scanner,USNO-B1.0, Sloan Digital Sky Survey, and Two Micron All Sky Survey, aswell as ROSAT, IRAS, NRAO VLA Sky Survey1The National RadioAstronomy Observatory is a facility of the National Science Foundationoperated under cooperative agreement by Associated Universities, Inc.,and Faint Images of the Radio Sky at Twenty cm catalogs, added updatedSIMBAD and NED data for the objects, and provided accurate DSS1 and DSS2positions and revised photometry. We also checked the objects for propermotion and variability. A refined classification for the low-dispersionspectra in the Digitized First Byurakan Survey was carried out. Therevised and updated catalogue of 1101 FBS BSOs is presented. The FBSBSOs catalogue can be used to study a complete sample of white dwarfs,hot subdwarfs, HBB stars, cataclysmic variables, bright active galacticnuclei, and to investigate individual interesting objects.
| The Century Survey Galactic Halo Project III: A Complete 4300 DEG2 Survey of Blue Horizontal Branch Stars in the Metal-Weak Thick Disk and Inner Halo
We present a complete spectroscopic survey of 2414 2MASS-selected bluehorizontal branch (BHB) candidates selected over 4300 deg2 ofthe sky. We identify 655 BHB stars in this non-kinematically selectedsample. We calculate the luminosity function of field BHB stars, andfind evidence for very few hot BHB stars in the field. The BHB starslocated at a distance from the Galactic plane |Z| < 4 kpc trace whatis clearly a metal-weak thick disk population, with a mean metallicityof [Fe/H] = -1.7, a rotation velocity gradient of dvrot/d|Z|= -28 ± 3.4 km s-1 in the region |Z| < 6 kpc, and adensity scale height of hZ = 1.26 ± 0.1 kpc. The BHBstars located at 5 < |Z| < 9 kpc are a predominantly inner-halopopulation, with a mean metallicity of [Fe/H] = -2.0 and a mean Galacticrotation of -4 ± 31 km s-1. We infer the density ofhalo and thick disk BHB stars is 104 ± 37 kpc-3 nearthe Sun, and the relative normalization of halo to thick-disk BHB starsis 4 ± 1% near the Sun.
| Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| DSS1/DSS2 astrometry for 1101 First Byurakan Survey blue stellar objects: Accurate positions and other results
Accurate measurements of the positions of 1101 First Byurakan Survey(FBS) blue stellar objects (the Second part of the FBS) have beencarried out on the DSS1 and DSS2 (red and blue images). To establish theaccuracy of the DSS1 and DSS2, measurements have been made for 153 AGNfor which absolute VLBI coordinates have been published. The rms errorsare: 0.45 arcsec for DSS1, 0.33 arcsec for DSS2 red, and 0.59 arcsec forDSS2 blue in each coordinate, the corresponding total positional errorsbeing 0.64 arcsec, 0.46 arcsec, and 0.83 arcsec, respectively. Thehighest accuracy (0.42 arcsec) is obtained by weighted averaging of theDSS1 and DSS2 red positions. It is shown that by using all three DSSimages accidental errors can be significantly reduced. The comparison ofDSS2 and DSS1 images made it possible to reveal positional differencesand proper motions for 78 objects (for 62 of these for the first time),including new high-probability candidate white dwarfs, and to findobjects showing strong variability, i.e. high-probability candidatecataclysmic variables.Table 1 is only available in electronic form at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/426/367
| Beyond the iron group: Heavy metals in hot subdwarfs
We report the discovery of strong photospheric resonance lines of GaIII, Ge IV, Sn IV and Pb IV in the UV spectra of more than two dozen sdBand sdOB stars at temperatures ranging from 22 000 K to 40 000 K. Linesof other heavy elements are also detected, however in these cases moreatomic data are needed. Based on these discoveries, we present ahypothesis to explain the apparent lack of silicon in sdB stars hotterthan 32 000 K. The existence of triply ionised Ge, Sn, and Pbsuggests that rather than silicon sinking deep into the photosphere, itis removed from the star in a fractionated stellar wind. This hypothesisprovides a challenge to diffusion models of sdB stars.Based on observations made with the NASA/ESA Hubble Space Telescope,which is operated by the Association of Universities for Research inAstronomy, Inc., under NASA contract NAS 5-26555. These observations areassociated with program #8635 and #5319.
| Studying the populations of our Galaxy using the kinematics of sdB stars
We have analysed the kinematics of a sample of 114 hot subdwarf stars.For 2/3 of the stars, new proper motions, spectroscopic and photometricdata are presented. The vast majority of the stars show a kinematicbehaviour that is similar to that of Thick Disk stars. Some stars havevelocities rather fitting to solar, i.e. Thin Disk, kinematics. About˜15 objects have orbital velocities which differ considerably fromthose of Disk stars. These are members of the Galactic Halo. Weinvestigated the velocity dispersions and calculated the orbits. Moststars feature orbits with disk character (eccentricity of less than0.5), a few reach far above the Galactic plane and have very eccentricorbits (eccentricity of more than 0.7). The intermediate eccentricityrange is poorly populated. This seems to indicate that the (Thick) Diskand the Halo are kinematically disjunct. Plotting a histogram of theorbit data points along z leads to the z-distance probabilitydistribution of the star; doing this for the whole sample leads to thez-distance probability distribution of the sample. The logarithmichistogram shows two slopes, each representing the scale height of apopulation. The disk component has a scale height of 0.9 (±0.1)kpc, which is consistent with earlier results and is similar to that ofthe Thick Disk. The other slope represents a component with a scaleheight ˜7 kpc, a much flatter gradient than for the diskcomponent. This shows that the vast majority of the sdBs are disk stars,but a Halo minority is present, too. The kinematic history andpopulation membership of the sdB stars on the whole is different fromthat of the cooler HBA stars, which are predominantly or evenexclusively Halo objects. This leads to the question, whether the HalosdB stars are of similar origin as the HBA stars, or whether theirkinematical behaviour possibly represents another origin, such asinfalling stellar aggregates or inner disk events.Based on data obtained at the 1.54 m telescope of the European SouthernObservatory, runs 58.D-0478, 60.D-0306, 62.L-0220, 64.L-0077,64.H-0023(A), 65.H-0250, 65.H-0341(A) and 68.D-0192(A).
| A Survey for Pulsating Hot B Subdwarfs in the Northern Hemisphere
We present the final results of a survey to search for pulsating hot Bsubdwarf (sdB) stars. We picked our candidates on the basis of theirvalues of Teff and logg, as estimated from availablequantitative optical spectroscopy. With the help of a three-channelphotometer, we gathered ``white-light'' light curves using a uniformsampling time of 10 s for a total of 74 stars. Our survey had a yield of~5.4%, leading to the discovery of detectable luminosity variations infour objects: PG 1047+003, KPD 2109+4401, KPD 1930+2752, and PG0014+067. For the light curves of the other 70 stars, we derive upperlimits on the amplitudes of possible periodic signals (in the periodwindow 20-1000 s) that range from ~0.05% of the mean brightness of thestar at an apparent magnitude of y~12 to ~0.20% at y~15. We use oursurvey results as well as those of others to discuss the location andextent of the empirical instability ``strip'' for pulsating sdB stars inthe logg-Teff diagram. We also address the question of thecoexistence of pulsators and nonvariable stars in the same region ofthat diagram. Based in part on observations gathered at theCanada-France-Hawaii Telescope, operated by the National ResearchCouncil of Canada, the Centre National de la Recherche Scientifique deFrance, and by the University of Hawaii.
| Physical parameters for subdwarf B stars with composite spectra
New intermediate-resolution spectra have been obtained for a number ofsubdwarf B stars having both single and composite spectra. Physicalparameters have been determined for the sdB stars and, incomposite-spectrum systems, their cool companions. For these binaries,we have developed a method which uses the blue-optical spectrum todetermine the effective temperatures of both stars, the surface gravityof the hot stars and the radius ratio of the system. The surface gravityof the cool star is measured using the infrared calcium triplet. Thesurface gravities of these cool companions identify them asmain-sequence stars with masses in the range 0.8-1.2 Msun,confirming a previous energy distribution analysis. There is alsoevidence that the composite-spectrum sdBs are more helium-poor thansingle-spectrum sdBs. Based on observations made with the Isaac Newtonand William Herschel Telescopes.
| Metal abundances of sdB stars
The surface abundance patterns of 13 sdB stars have been determined fromhigh resolution, high S/N, optical spectra. As typical in early B typestars, the metal lines are few and very weak. The metal abundancepatterns are compared with the atmospheric parameters to search forpossible trends, which are predicted by diffusion theory. However, it isremarkable that some metals (e.g. N, Mg, Fe) have similar abundancesirrespective of the stellar parameters, whereas other metals (e.g. C, O)and the helium abundances vary considerably from star to star. Threepeculiar sdB stars were found which show an enormous enrichment of irongroup elements. An isotopic anomaly of helium has been found in two sdBstars. In these stars 4He is largely replaced by the isotope3He. We discovered additionally four single lined, shortperiod radial velocity variable sdB stars and measured their radialvelocity curves.
| Physical parameters of sdB stars from spectral energy distributions
The atmospheric parameters of 34 hot subdwarf B stars have been obtainedusing a combination of 61 short and long-wave IUE spectra, together withnew and existing optical and infrared photometric data. Using a grid ofhigh-gravity helium-deficient model atmospheres and a chi2-minimization procedure, 15 single sdB stars and 19composite systems, containing a hot subdwarf B star and a coolmain-sequence companion, were analyzed. From the (log L-log T_eff)diagram of our results, we conclude that the majority of the coolcompanions to our sample of binary sdB stars are main sequence stars, inthe range of 4000 < Teff / K < 6000 and mass 0.8
| Infrared flux excesses from hot subdwarfs. II. 72 more objects
In our search, started in February, 1994, for JHK excess fluxes amongthe hot subdwarf population as an indicator for the presence of binarycompanions, results for 72 more hot objects (=63 hot subdwarfs + 1Horizontal Branch B star + 7 white dwarfs + 1 non-subdwarf object)observed with the Carlos Sanchez CVF IR photometer (in June and October,1994), are presented. The exact number of binary hot subdwarfs hasgained renewed importance after the recent discovery of pulsators withG-F companions. The total number of candidates we propose may help toset some constraints; for example, out of 41 objects with excesses, 13may have G-type binary companions. From our new sample, 14 discoveriesof binary candidates have been found: BD+25 4655, Feige 108, HD 4539, HD149382, HD 216135, KPD 2109+440, LSI+63 198, LSIV+10 9, LSV+22 38, PG0011+221, PG 0116+242, PG 0314+103, PG 2151+100 and TON 139. Besides, 2more from reanalysis of February, 1994, data - BD+37 1977 and BD+481777, may now be found to be IR excess candidates. Two suspectedbinaries, PB 8555 and SB 7, are also confirmed. By fitting \cite[Kurucz(1993)]{kur93} model spectra and assuming zero-age main sequencecompanions, we find upper limits on the subdwarf gravities. Thedistributions of upper limits on log(g), mostly between about 5.25 and6.5, are nearly identical for both sdBs and sdOs. Figure~1 is onlyavailable in the electronic version of the paper(http://www.edpsciences.com)
| The detection of binary companions to subdwarf B stars
Intermediate dispersion spectroscopy of a sample of 40 hot subdwarf Bstars between 5500 and 9000Angstroms has been obtained. The sampleincludes a large fraction of targets which have been studiedphotometrically. Seven targets show strong lines arising from theinfrared Caii triplet, the unequivocal signature of a cool companion.The positiveCaii identifications include known photometric binaries andnew targets; all are associated with a photometric red excess. Assuminga canonical value for the subdwarf luminosity, all of the detectedcompanions are overluminous compared with the main sequence. Thedetection procedure indicates an improved and more secure method for themeasurement of the binary frequency of hot subdwarfs.
| Close Binary White Dwarf Systems: Numerous New Detections and Their Interpretation
We describe radial velocity observations of a large sample of apparentlysingle white dwarfs (WDs), obtained in a long-term effort to discoverclose double-degenerate (DD) pairs, which might comprise viable Type Iasupernova (SN Ia) progenitors. We augment the WD sample with apreviously observed sample of apparently single subdwarf B (sdB) stars,which are believed to evolve directly to the WD cooling sequence afterthe cessation of core helium burning. We have identified 18 new radialvelocity variables, including five confirmed sdB + WD short-periodpairs. Our observations are in general agreement with the predictions ofthe theory of binary star evolution. We describe a numerical method toevaluate the detection efficiency of the survey and estimate the numberof binary systems not detected because of the effects of varying orbitalinclination, orbital phase at the epoch of the first observation, andthe actual temporal sampling of each object in the sample. Follow-upobservations are in progress to solve for the orbital parameters of thecandidate velocity variables.
| Hot subdwarf stars: galactic orbits and distribution perpendicular to the plane.
The spatial distribution and the population nature of subdwarf B typestars in the galaxy is investigated based on the kinematics of thesestars. With new and available proper motions, radial velocities, anddistances, the orbits of 41 stars have been calculated using a galacticmass model. The orbits are well behaved and 10 stars reach to|z|>=2kpc. Many orbits are very eccentric, reaching in to just 2kpcfrom the galactic centre, or veering out to beyond 20kpc. None of thestars can be identified uniquely as classical Population II objects. Theaverage eccentricity ecc of the orbits of our sample is 0.24, theaverage normalised z-extent nze of the orbits is 0.16, and theasymmetric drift of our sample is -36km/s. This suggests that our sampleof sdB stars is part of a population of thick disk stars. A statisticalanalysis of the orbits shows that the subdwarf stars have a spatialdistribution in z compatible with an exponential one with a scale heighth_z_ of about 1.0kpc. However, since only few stars reach to large z thespatial distribution is only well defined to z =~2kpc. The distributionin z shows a relative minimum near z=0pc and has maxima near z=300pc.This reflects the smaller probability to find the stars in the disk thanaway from the disk, as expected for any orbit reaching to larger z.Scale height studies based on limited samples of stars in specifieddirections can therefore easily be flawed when they do not reach tolarge enough distances to overcome this aspect of the z-distribution.
| Proper motions of the hot subdwarfs. The kinematic population membership of the sdB.
We report on first results from an ongoing program to measure andanalyze proper motions for hot subdwarf and white dwarf stars, with theaim of determining to which stellar population sdB stars (in the Vmagnitude range 10.5 to 14.5) belong. Ours is the largest sample of hotsubdwarf proper motions measured to date. Our kinematic analysissuggests that the parent population of these hydrogen-rich sdB stars isas old or older than the old disk. We measure the absolute magnitude ofthe sdB in the field as M_V_=4.5, providing independent confirmation ofabsolute V magnitude estimates for these stars from clusters andspectroscopic analyses. Provided it can be shown that the sdO starsevolve from the sdB, then the sdO absolute V magnitude distribution isabout 1 magnitude brighter than for the sdB, and 1 magnitude wider.
| A Catalog of Candidate Field Horizontal-Branch and A-Type Stars. II.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..103..433B&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.
| Atmospheric parameters of field subdwarf B stars
High signal-to-noise ratio optical spectrophotometry of a sample offield subluminous B stars drawn largely from the Palomar Greenultraviolet-excess survey is analyzed with a new grid of modelatmospheres and synthetic spectra. The stellar effective temperatures,surface gravities, and photospheric helium abundances are determinedsimultaneously from a detailed analysis of hydrogen and heliumabsorption line profiles. The derived temperatures and gravities placethe subluminous B stars in the theoroetical Hertzsprung-Russell (H-R)diagram along and bounded below by theoretical sequences of the zero-ageextended horizontal branch, lending strong support to the hypothesisthat these stars are composed of helium-burning cores of approximately0.5 solar mass overlain by very thin layers of hydrogen (approximatelyless than 0.02 solar mass). Various scenarios for their pastevolutionary history are examined in the context of their probablefuture evolution into white dwarfs of lower than average mass.
| A high-latitude Be star.
A faint (V = 13.11, B-V = -0.15) high altitude (b = +640) star discovered by G. Haro to have Hα in emission is of type BO-B 1, and has the appearance of a typical Population I Be star. If that were so, there would be difficulty in accounting for the star's presence at z = 19.7 kpc if it were formed near the plane no more than 1-2 x 10 years ago. The Balmer absorptionwings, outside the emission cores, make possible an estimate of log g bycomparison with other early B-type stars of various luminosities; theresult is log g is about 4.7, which shows that Haro's star lies belowthe main-sequence. If it is a Population II star with mass about 0.6 Me,then Mv is about +2, and the distance is only 1.6 kpc. Possibly Haro'sstar is in transition between the AGB and planetary nebula central starstages. A search of globular clusters for similar objects isrecommended.
| General catalogue of AP and AM stars
A catalog of all the known Ap and Am stars, containing a total of 6684objects, was prepared. The few stars that were wrongly considered as Apor Am star are noted as well as some others for which their identity asAp or Am stars is not yet well established. The catalog gives theidentificators and the main observational data for each star, includingthe magnitude, color, spectral type, duplicity, periodicity, magneticfield, and projected rotational velocity.
| The First Byurakan Spectral Sky Survey. Blue Stellar Objects. III. Zone DEC=+43
Not Available
| A catalogue of spectroscopically identified hot subdwarf stars.
Not Available
| Spectral Analysis of Hot Subdwarfs (Fieldversus Globular Cluster Population)
Not Available
| The Palomar-Green catalog of ultraviolet-excess stellar objects
The Palomar-Green Catalog of Ultraviolet Excess Stellar Objects ispresented, with data consisting of positions on the sky accurate toabout 8 arcsec in each coordinate, photographic B-magnitudes accurate to0.29 mag, spectral types, some cross references, and photoelectricbroadband, multichannel, and Stromgren colors when available. Extensivediscussion is given on magnitude calibration using a combination ofphotoelectric measurements and star count modeling, and on thestatistical completeness of the sample based on internal and externaltests. Of the 1874 objects in the catalog, 1715 comprise a statisticallycomplete sample covering 10,714 square degrees from 266 fields taken onthe Palomar 18-inch (46-cm) Schmidt telescope. Limiting magnitudes varyfrom field to field, distributed around B = 16.1 mag, ranging from 15.49to 16.67. The dominant population is that of the hot, hydrogenatmosphere subdwarfs, the sdB stars, which comprise nearly 40 percent ofthe sample. At 16th magnitude, the hot subdwarf (sdB, sdO) number countsare increasing by about a factor of 2 per mag, the hot white dwarfs by 4per mag, and quasars by 8 per mag. The result is a very different mix ofspectral types expected at 18th mag than is found at 16th mag. Thesuggestion is made that the sdB stars are part of the old disk ratherthan a halo population.
| Studies of hot B subdwarfs. III - Carbon, nitrogen, and silicon abundances in three sdB stars
Optical and high-dispersion IUE observations of three hot B subdwarfs(UV 1758 + 36, Ton S-227, and Feige 65) are presented. These data areanalyzed with model atmosphere techniques, and element abundances for C,N, and Si are derived. The abundances are either near (N) or below (C,Si) the solar value; large variations (1) in the extent ofunderabundances of carbon and silicon among the objects, as well as (2)in the abundances (with respect to the solar values) characterizing eachstar are observed. A preliminary interpretation of the observedvariations in these and other hot subdwarfs in terms of radiative forcesdisrupting the downward diffusion of heavy elements is presented.
| Picture gallery - A structured presentation of OAO-2 photometric data supported by OAO-2 spectrophotometric data and UBV, ANS and TD1 observations
Graphs are presented for the stellar fluxes of 531 stars in the5500-1330 A wavelength range, which have been divided into 52 categorieson the basis of spectral types. The merging of medium band interferencefilter photometry, UBV photometry, ANS photometry and TD1 fluxes, aswell as the ordering of the objects, should prove helpful in studies ofinterstellar reddening, luminosity effects, bandwidth effects, andcomparisons with model stellar atmospheres. The agreement between thevarious UV photometric systems for early-type stars is generally betterthan 0.10 mag. A list of stars whose photometric properties indicatestellar or interstellar anomalies is also provided.
| Further Studies of A-Stars and F-Stars in the Region of the North Galactic Pole - Part Four - a Catalogue of Uvbyr Photometry and Derived Quantities
Not Available
| Ultraviolet photometry from the Orbiting Astronomical Observatory. XXXIV - Filter photometry of 531 stars of diverse types
Ultraviolet magnitudes for 531 stars observed with the WisconsinExperiment Package on OAO 2 are tabulated. It is noted that these dataconstitute a subset of the OAO 2 data on file at the National SpaceScience Data Center. The tabulation contains previously published dataall reduced to a uniform magnitude system. It is pointed out that theobservations were obtained with the medium band interference filterphotometers. Eleven magnitudes are given designated by their centroidwavelengths.
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