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The ROSAT all-sky survey catalogue of optically bright OB-type stars.
For the detailed statistical analysis of the X-ray emission of hot starswe selected all stars of spectral type O and B listed in the Yale BrightStar Catalogue and searched for them in the ROSAT All-Sky Survey. Inthis paper we describe the selection and preparation of the data andpresent a compilation of the derived X-ray data for a complete sample ofbright OB stars.
| Note on the radial velocities of 10 southern stars.
Echelle spectrograms of the stars HD 55857, 57219, 62623, 83058, 84400,86087, 86523, 89461, 90898, 96446 have been obtained in 1991 as part ofan investigation of stars previously classified as both chemicallypeculiar and high luminosity B and A stars. Radial velocity measurementsfor HD 83058, 84400 and 86087 are internally discordant and should berepeated. In the case of HD 55857, 57219, 62623 and 96466 the resultsare in fair agreement with earlier measurements but for HD 86523 ourresult is substantially different from the earlier ones. For HD 89461and 90898 no comparison with other sources was available. With nofurther observational opportunities in view (due to increasing demand ontelescopes), these preliminary results are presented here.
| Globular cluster distances from the RR Lyrae log(period)-infrared magnitude relation
The present determinations of log(period)-2.2 micron IR relationship forRR Lyr stars in eight clusters indicate no sign of scatter in therelation apart from observational error. It is suggested that veryaccurate relative distances, insensitive to both reddening errors andthe effects of metallicity, are obtainable, although mass differencesbetween variables in different clusters may still introduce relativedistance uncertainties. A comparison of the absolute calibration of Kmagnitudes of two field stars obtained with an IR-flux method form ofthe Baade-Wesselink analysis to three other sets of distancemeasurements shows good agreement with those of Richer and Fahlman(1987).
| VBLUW-photometry of stars in small fields around 13 planetary nebulae
Observations of stars in small fields around 13 planetary nebulae, madeusing the Walraven five-channel VBLUW photometer, are presented anddescribed. The fields are found to have a radius of about 0.3 deg. Thefinding charts for the measured stars are given. It is shown that moststars are brighter than mV of about 14 mag and that the photometry hasan accuracy of better than 1 percent, except for stars that are observedwith short test-integrations and for stars fainter than mV of about 14mag. The photometric data for all stars are presented, together with alist of identifications and spectral types.
| The local system of early type stars - Spatial extent and kinematics
Published uvby and H-beta photometric data and proper motions arecompiled and analyzed to characterize the structure and kinematics ofthe bright early-type O-A0 stars in the solar vicinity, with a focus onthe Gould belt. The selection and calibration techniques are explained,and the data are presented in extensive tables and graphs and discussedin detail. The Gould belt stars of age less than 20 Myr are shown togive belt inclination 19 deg to the Galactic plane and node-lineorientation in the direction of Galactic rotation, while the symmetricaldistribution about the Galactic plane and kinematic properties (purecircular differential rotation) of the belt stars over 60 Myr oldresemble those of fainter nonbelt stars of all ages. The unresolveddiscrepancy between the expansion observed in the youngest nearby starsand the predictions of simple models of expansion from a point isattributed to the inhomogeneous distribution of interstellar matter.
| Radial velocities of bright southern stars. I - 139 B-type HR and FK stars
Radial velocity determinations for 139 southern B stars in the BrightStar, FK4, and FK4 Supplement catalogues and for 53 bright southernlate-type stars are presented, based on coudespectrograms taken with theESO 1.5 m telescope at La Silla. The programs, observations,measurements, and reductions are described. Among the data presented arethe visual magnitude, spectral class, mean error, E/T variabilityparameter, velocity of interstellar lines, and rotation class.
| Spectral classification from the ultraviolet line features of S2/68 spectra. V - Supplement series
The paper presents the ultraviolet classification of more than 450 B-Aand F spectra obtained with the sky survey telescope mounted on the TD1satellite. Concerning abnormal objects, attention is given to the Bestars, the binary stars, the helium weak stars, and the lambda Booobjects. With regard to Be stars, it is concluded that the 1930 Awavelength feature is linked to the existence of either shell structuresor Fe II emission lines in the visual spectral range. In addition, it issuggested that stellar spectra at wavelengths of 1410, 1610-20 and 2400A are equivalent to the He-weak group in the classical range.
| 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
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תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | מפרש |
| התרוממות ימנית: | 10h18m28.20s |
| סירוב: | -41°40'06.0" |
| גודל גלוי: | 5.96 |
| מרחק: | 168.919 פארסק |
| תנועה נכונה: | -28.6 |
| תנועה נכונה: | 4.4 |
| B-T magnitude: | 5.884 |
| V-T magnitude: | 5.947 |
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