Abstract. Radial velocities have been determined for a sample of 2930 B2-F5 stars, 95% observed by the Hipparcos satellite in the north hemisphere and 80% without reliable radial velocity up to now. Observations were obtained at the Observatoire de Haute Provence with a dispersion of 80Å mm −1 with the aim of studying stellar and galactic dynamics. Radial velocities have been measured by correlation with templates of the same spectral class. The mean obtained precision is 3.0 km s −1 with three observations. A new MK spectral classification is estimated for all stars.
Abstract. Many studies recently have been performed to determine the velocity vector of the Sun, mainly using the latest data on proper motions and parallaxes given by the Hipparcos satellite. We wished to carry out a similar study using totally independent data: the numerous radial velocities (RV ) obtained with the Fehrenbach Objective Prisms (PO). This method allows the determination of the RV s of all the stars contained in the same field. These RV s are relative to each other but are linked to the IAU standard system by means of at least two calibration stars of known RV belonging to that field. These data are very homogeneous. We discuss the precision of the results, and deduce that this material is relevant for the computation of the movement of the Sun towards its Apex. We have performed several studies: 1) With 6965 stars of magnitudes ranging from 7 to 10, measured with the small PO of 15 cm diameter (PPO), with the whole sample and with the same sample split into blue and red stars. 2) With 11 978 stars of magnitudes ranging from 7 to 11, by adding to the previous sample the stars measured with the 60 cm diameter PO associated with the Schmidt telescope of Observatoire de Haute Provence (SPO). The results of both studies are consistent. 3) We have estimated the distance D of all stars studied and determined U , V , W and S for four groups of stars selected according to their distances: D < 100, 100 < D < 300, 300 < D < 500, D > 500 parsecs. We have determined the variation of U , V , W and S with respect to the distance of the stars. The variation of U , V and S is linear up to 500 parsecs. We can consider that W is constant.
Abstract. We publish 1879 radial velocities of stars distributed in 105 fields of 4• × 4• . We continue the PPO series (Fehrenbach et al. 1987;Duflot et al. 1990Duflot et al. , 1992Duflot et al. and 1995, using the Fehrenbach objective prism method.
La méthode de mesure des vitesses radiales au prisme objectif à champ normal que nous employons à l'Observatoire de Haute Provence depuis de nombreuses années (Fehrenbach 1947, 1948, 1955) est la méthode idéale pour la recherche des étoiles de grande luminosité, membres des Grand et Petit Nuages de Magellan.
L’étude faite par Ch. Fehrenbach prouve que les Prismes-Objectifs à champ normal (PO) sont les instruments parfaitement adaptés a une étude statistique des mouvements stellaires dans la galaxie.Les PO souffraient jusqu’à ces dernières années, d’un dépouillement laborieux, inadapté à leur capacité. Les moyens informatisés actuels donnent la possibilité de les utiliser avec le rendement voulu.Au début de 1982, le groupe du satellite Hipparcos a fait une demande de mesures de vitesses radiales (VR) pour compléter les informations que donnera le satellite. Depuis cette date, nous nous sommes engagés dans la mesure des VR des étoiles brillantes (mg < 9,0) qui sont une partie essentielle du programme Hipparcos. En particulier, nous avons choisi des champs où se groupaient des étoiles des premiers types spectraux (≤ F5) dont la VR était inconnue. Les étoiles des types plus avancés (> F5) peuvent en effet être mesurées, avec plus de précision, avec la méthode de spectrocorrelation directe sur le ciel. Signalons que nous mesurons cependant, dans les champs choisis, les étoiles de tous les types spectraux
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