New periodic variables from the Hipparcos epoch photometry Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.
Mesures de vitesses radiales. VIII. Accompagnement AU sol DU programme d'observation DU satellite HIPPARCOS We publish 1879 radial velocities of stars distributed in 105 fields of4^{\circ} \times 4^{\circ}. We continue the PPO series \cite[(Fehrenbachet al. 1987;]{Feh87} \cite[Duflot et al. 1990, 1992 and 1995),]{Du90}using the Fehrenbach objective prism method. Table 1 only available inelectronic form at CDS via to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
Interstellar polarization at high galactic latitudes from distant stars. 2: First results for Z less than or equal to 600 PC We present the first results from our Crimean-Tuorla program forpolarimetry of distant stars at high galactic latitudes. The availableobservations reveal a clear increase in the interstellar linearpolarization of A and F stars, up to Z approximately equals 600 pc whereone reaches PV approximately equals 0.25%. This means anaverage AB greater than or equal to 0.11 mag over thenorthern polar cap for the diffuse component of the interstellarextinction that we are probing. There is no clear indication in the datathat the asymptotic level of PV has been reached, and withfuture observations above Z = 600 pc we shall investigate this question.The trend found is in agreement with the stellar reddening analysis byTeerikorpi (1990). The directions of the plane of vibration are inagreement with Markkanen's (1979) analysis of closer (Z less than 200pc) stars in his 'Area II'. Outside of this area we define two sectors Band C which encompass the Local Spiral Arm and had little stars inprevious investigations. Here the polarization vectors deviate stronglyfrom those in Markkanen's Area II, where one is probably looking at aninterarm region, close to the edge of the Local Spiral Arm. Ourmeasurements indicate for B and C average polarization vectorsconsistent with the direction l approximately equals 110 deg obtained byother authors for the magnetic field in the Local Spiral Arm using therotation measure method.
