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Apsidal motion in southern eccentric eclipsing binaries: GL Car, QX Car, NO Pup and V366 Pup
The study of apsidal motion in eccentric eclipsing binaries (EEB)provides an important observational test of theoretical models ofstellar structure and evolution. The Southern hemisphere contains manyinteresting and also neglected binary systems. New accuratephotoelectric times of minimum light have been obtained for the detachedearly-type Southern hemisphere EEB GL Car (P = 2.42d,e = 0.15), QX Car(4.48d, 0.15), NO Pup (1.26d, 0.13) and V366 Pup (2.48d, 0.47). The O-Cdiagrams are analysed using all reliable timings found in the literatureand improved or new values for the elements of the apsidal motion arecomputed. We find more precise, relatively short periods of apsidalmotion of about 25.2, 362, 38.3 and 285yr and corresponding internalstructure constants, log k2, -1.88, -2.08, -2.32 and -2.38for GL Car, QX Car, NO Pup and V366 Pup, respectively, with theassumption that the component stars rotate pseudo-synchronously. Therelativistic effects are small, being about 3-12 per cent of the totalapsidal motion rate in all systems.Based on observations made at the South Africa Astronomical Observatory,Sutherland, South Africa and Mt John University Observatory, Universityof Canterbury, Lake Tekapo, New Zealand.E-mail: wolf@cesnet.cz
| Hyades and Sirius supercluster members brighter than magnitude (V) 7.1. II - Right ascension six to twelve hours
The present star sample is contained in the Bright Star Catalogue andits Supplement, augmented with a further supplement of 788 stars foundduring various observing programs over the past 40 years. Accurate,four-color and H-beta, or (RI), photometry is available for most of thesupercluster members. The criteria for membership are the comparisons ofthe proper motion, radial velocity, and luminosity obtained from thesupercluster parameters with the observed motions and the luminosityderived from the photometric parameters. New proper motions, based onall available catalogs, have been derived for the additional 788 starsdiscussed here, as well as all supercluster members.
| Estimation of spectral classifications for bright southern stars with interesting Stromgren indices
This paper investigates the degree of success with which uvby photometrycan be applied to predict spectral classifications for 947 A, F, and Gstars brighter than an apparent magnitude of 8.3 and with four-colorindices indicating some kind of interesting, unusual, or peculiarspectrum. One or several possible spectral classifications are estimatedfor each star from photometry alone, double stars are distinguished, andthe estimates are compared with published classifications. The resultsshow that the framework provided by uvby photometry can be extended toinclude most G and K stars, reddened stars, peculiar stars, and certaintypes of double star.
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