New determination of the solar apex

Abstract

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.

High-resolution spectroscopic observations of the metal-poor, chemically peculiar, and high velocity Fehrenbach & Duflot star

“…This value is in good agreement with the value v rad = +440 km s −1 obtained by Fehrenbach & Duflot (1981).…”

“…The Fehrenbach & Duflot star (=2MASS J05025386-6544207, hereafter the Feh-Duf star according to SIMBAD designation) was discovered in 1981 by Fehrenbach & Duflot (1981) during their measurements of radial velocities of stars in the region of the Large Magellanic Cloud. They found that this star has a very high radial velocity (+440 km s −1 ) and also displays exceedingly strong CH absorption bands in its spectrum.…”

The SPECTROSCOPIC ORBITS OF FIVE Γ DORADUS STARS

“…Their radial velocities showed that the star had a radial velocity range of nearly 20 km s −1 , indicating that it is likely to be a spectroscopic binary. Kaye & Fekel (2003) used the velocities of Fehrenbach et al (1987) and Henry & Fekel (2002) to obtain a preliminary orbit with a period of 31.95 days.…”

Massive luminous early type stars in the LMC

“…Adopting a distance modulus of the LMC The systematic separation of stars in the direction of the Magellanic Clouds into member stars and galactic foreground stars has been initiated by Fehrenbach & Duflot (1970). These first lists were supplemented by numerous authors (Ardeberg et al 1972;Fehrenbach & Duflot 1973, 1974Brunet et al 1973Brunet et al , 1975Isserstedt 1975aIsserstedt , 1979Isserstedt , 1982Rousseau et al 1978) with additional stars and photometric measurements. However, there are problems in combining these data:…”