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Radial velocities in three fields along the southern galactic equator A list of radial velocities for 764 stars is given for three fields inthe Vela-Carina region of the galaxy. They were obtained from GPO-platestaken at La Silla and reduced following Fehrenbach's method.Slit-spectra were collected with the 152 cm-spectrographic telescope atLa Silla, to derive an accurate radial velocity for a sufficient numberof calibration stars: out of the 29 stars, 26 had no formerly publishedvalue. The global motions of 10 to 14 km/s can be considered as normalon the basis of galactic rotation. Some stars, however, show highvelocities, and are therefore marked with one or two asterisks in thetable.
| Five-colour photometry of early-type stars in the direction of galactic X-ray sources The results of five-color (Walraven system) photometry of 551 O- andB-type stars located in 17 fields of a few square degrees aroundgalactic X-ray sources are presented. From a comparison ofreddening-free combinations of color indices with theoretical values,calculated for model atmospheres of Kurucz (1979), effective temperatureand surface gravity for these stars are derived. In addition theirabsolute magnitude are determined by combining these parameters with theresults of evolutionary calculations of massive stars. These effectivetemperatures are in good agreement with the temperature scale ofBohm-Vitense (1981) for stars of luminosity classes II to V. For thesupergiants the effective temperatures are about 40 percent higher. Forstars of luminosity classes III to V the absolute magnitudes agree wellwith the results of independent luminosity calibrations of spectraltypes, but for brighter stars they deviate systematically. Thephotometric data are also used to study the interstellar reddening inthe direction of the X-ray sources.
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Takýmyýldýz: | Yelken |
Sað Açýklýk: | 09h13m08.69s |
Yükselim: | -53°30'17.3" |
Görünürdeki Parlaklýk: | 7.246 |
Uzaklýk: | 185.185 parsek |
özdevim Sað Açýklýk: | -9.9 |
özdevim Yükselim: | 9 |
B-T magnitude: | 7.209 |
V-T magnitude: | 7.243 |
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