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Four-colour photometry of eclipsing binaries. XL. uvby light curves for the B-type systems DW Carinae, BF Centauri, AC Velorum, and NSV 5783
Aims.In order to increase the limited number of B-stars with accuratelyknown dimensions, and also the number of well studied eclipsing binariesin open clusters, we have undertaken observations and studies of foursouthern double-lined eclipsing B-type binaries; DW Car, BF Cen, AC Vel,and NSV 5783. Methods: .Complete {uvby} light curves were observedbetween January 1982 and April 1991 at the Danish 0.5 m telescope at ESOLa Silla, since 1985 known as the Strömgren Automatic Telescope(SAT). Standard indices for the systems and the comparison stars, aswell as additional minima observations for AC Vel, have been obtainedlater at SAT. For DW Car and AC Vel, high-resolution spectra fordefinitive spectroscopic orbits have also been obtained; they arepresented as part of the detailed analyses of these systems. A fewspectra of NSV 5783 are included in the present paper. Results:.For all four systems, the first modern accurate light curves have beenestablished. DW Car is a detached system consisting of two nearlyidentical components. It is member of the young open cluster Cr228. Adetailed analysis, based on the new light curves and 29 high-resolutionspectra, is published separately. BF Cen is semidetached and is memberof NGC 3766. Modern spectra are needed for a detailed study. AC Vel is adetached system with at least one more star. A full analysis, based onthe new light curves and 18 high-resolution spectra, is publishedseparately. NSV 5783 is discovered to be an eclipsing binary consistingof two well-detached components in an 11-day period eccentric (e = 0.18)orbit. Secondary eclipse is practically total. From the light curves anda few high-resolution spectra, accurate photometric elements andpreliminary absolute dimensions have been determined. The quite similarcomponents have masses of about 5 Mȯ and radii of about3.5 Rȯ, and they seem to have evolved just slightly offthe ZAMS. The measured rotational velocities (≈150 kms-1) are about 6 times those corresponding topseudosynchronization.
| The β Cephei variable in the eclipsing binary HD 92024. I. Determination of the orbit
HD 92024 is a member of the open cluster NGC3293; it is the only eclipsing binary system with a β Cepheicomponent known in the southern hemisphere. This paper presents thefirst spectroscopic analysis of the single-lined binary and provides anorbital analysis based on recent high-resolution spectroscopy andphotometry. A procedure to derive orbital elements with minimalinfluence of the pulsational line-profile variations on the radialvelocities is applied, and we find the stellar masses to be 15.0+3.0-4.0Mȯ and 3.0±0.5 Mȯ respectively, and radii of8.4±0.8 Rȯ, 2.1±0.4 Rȯ. The temperatures are 25500±500 K and 12 500±1000 K. The surface gravity values oflog g= 3.77±0.08 and 4.27±0.18 indicate that the binaryconsists of an evolved early B-type primary and a late-B main sequencecompanion. The resulting distance 2.8±0.3 kpc and systemicvelocity -16 km s-1 confirm cluster membership. Theoretical stellarmodels indicate an age of 10-13 Myr, somewhat higher than theliterature value for the brightest members of NGC 3293.Based on observations made with ESO Telescopes at the La SillaObservatory, Chile, under programmes 66.D-0297, 67.D-0023, 68.D-028, andwith the Strömgren Automatic Telescope, La Silla.
| The Carina Spiral Feature: Strömgren-Hβ photometry approach. I. The photometric data-base
A data-base collating all uvbybeta photometry available at present forO-B9 stars brighter than 10th visual magnitude in the field of theCarina Spiral Feature is presented. The completeness and homogeneity ofthe data-base are discussed.Based on CDS data.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/410/523
| Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Stromgren and Hβ photometry of OB stars in the region of the Carina Spiral Feature
Stromgren and Hβ photometry of 130 stars in the Carina section ofthe Milky Way is presented. The color excesses and the distances of allstars are obtained. A good agreement is found between the CM and HRdiagrams and the spatial distribution of these stars. Tables 1, 2, 4 and5 are only available in electronic form at the CDS via anonymous ftp to130.79.128.5 or via http://cdsweb.u-strasbg.fr/Abstract.html
| Bright blue stars in VELA observed with the 'Glazar' space telescope
Seventy-one stars brighter than about 9 m have been detected at 1640 Ain the Vela region with the space telescope Glazar. It is shown thatmost of the detected stars belong to a B-type stellar association at adistance of 460 pc and to two OB stellar associations at distances of1100 pc and 1700 pc. The existence of B-type stellar association at adistance of 110 pc is suspected. A new O-type star cluster, which is apossible nucleus of the OB stellar association at 1700 pc, has beendetected. The distribution of the absorbing matter in the observed areais studied. We presume that the stars HD 75 063 and 76 534 are probablyembedded in a circumstellar dust shell. All observed stars, includingthose with unknown spectra, are early type stars.
| Distribution of hot stars and interstellar dust in Carina.
Not Available
| Observations of a region of the Carina OB 1 association using the "Glazar" space telescope.
Not Available
| Multicolor photometric and spectroscopic observations of the van den Bergh and Hagen cluster no. 99
Multicolor photometry and MK classification spectroscopy have beenobtained for the sparse collection of stars known as van den Bergh andHagen cluster No. 99. The group appears to be a true open clustercomposed of at least 24 members with a mean reddening of E(B-V) = 0.05mag, a mean distance modulus of 8.30 mag and an age of approximately 100million years.
| UBV Photometry of 500 Southern Stars [erratum: 1973MNSSA..32...48C]
Not Available
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| Takýmyýldýz: | Karina |
| Sað Açýklýk: | 10h36m32.79s |
| Yükselim: | -59°11'25.2" |
| Görünürdeki Parlaklýk: | 7.031 |
| Uzaklýk: | 512.821 parsek |
| özdevim Sað Açýklýk: | -14.1 |
| özdevim Yükselim: | 2.4 |
| B-T magnitude: | 6.895 |
| V-T magnitude: | 7.02 |
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