Search Publications
Polarimetric investigatio, on interstellar dust within 50 PC from the sun.
Leroy, J. L.
We have analyzed the polarization catalogue, for 1000 stars closer than 50 Pc, which has been presented in a companion paper. Although the accuracy of the measurements is generally very good (better than 0.02% for more than 700 stars), the catalogue contains essentially unpolarized stars, which is to be related to the well known depletion of dust …
Optical polarization of 1000 stars within 50 PC from the Sun
Leroy, J. L.
We have prepared a catalogue of optical polarization measurements for 1000 stars closer than 50 parsecs from the Sun. The distances, which are presently those given in the Sky Catalogue 2000.0, 2nd edition (Hirshfeld et al. 1991) are provisional: they will be replaced later by the much safer parallaxes which will result from the Hipparcos mission.…
Absolute Proper Motion and Space Motion of the Globular Cluster M15
Le Campion, J. -F.; Odenkirchen, M.; Geffert, M. +1 more
We have separated cluster members and field stars for stars in a region around the globular cluster M 15. The membership of ultraviolet bright stars of M 15 is discussed. The absolute proper motion of M 15 has been determined with respect to the PPM catalogue. An extragalactic calibration of the proper motions has been performed. The calibration w…
Hubble Space Telescope Astrometric Observations of Pre-Main Sequence Stars from the HIPPARCOS Program
Badiali, M.; Cardini, D.; Emanuele, A. +6 more
We report on the first set of high angular resolution observations with Fine Guidance Sensor (FGS) #3 aboard the Hubble Space Telescope of a sample of T-Tauri and Herbig Ae/Be pre-main sequence stars, which have also been observed with the HIPPARCOS satellite. Among the 5 Ae/Be stars observed so far of particular interest is the new double HIPPARC…
Determination of field distortion by a plate-overlap method.
Abad, C.
An automated reduction method for determining field distortion common to all plates based on a black-adjustment method proposed by Stock (1981) is demonstrated on the Paris Zone of the Astrographic Catalog. It is shown that the FK5 is suitable as the only reference source for zone catalogs.
HIPPARCOS link with Carte du Ciel triple images.
Tucholke, H. -J.; Brosche, P.; Guibert, J. +3 more
This study for the first time investigates the possibility of deriving astrometric positions for bright stars on Carte du Ciel (CdC) plates, whose triple images are not separable. The field from the Bonn Hipparcos Extragalactic Link Programme with the BL Lac object OJ 287 has been selected. The triple images on the CdC plate were modelled by three…
Anomalous proper motions in the Cygnus superbubble region.
Jordi, C.; Torra, J.; Comeron, F. +1 more
In an analysis of proper motions of O and B stars contained in the Input Catalogue for Hipparcos, we have found a clear deviation from the expected pattern of systematic motions which can be readily identified with the associations Cygnus OB1 and Cygnus OB9, located near the edge of the Cygnus Superbubble. The anomalous motions are directed outwar…
CCD astrometry and instrumental (Delta)V photometry of wide visual double stars. III. Differential measurements of often observed southern pairs.
Sinachopoulos, D.; van Dessel, E.
We present accurate relative positions and instrumental visual (Bessel V) magnitude differences of southern wide star components. The mean accuracy of the angular separation is 0.02 arcsecs, which corresponds to 1.5 micron on the CCD chip, and of magnitude difference 0.007 mag/exposure. The program pairs are targets of the HIPPARCOS mission and th…
CPC2: The Second Cape Photographic Catalogue. I - History, observations and plate measurements
Zacharias, N.; Murray, C. A.; de Vegt, C. +3 more
The Second Cape Photographic Catalog is discussed. The observations and measurements involved in the preparation of the first version of the catalog are described. The present stellar reference frame is reviewed, and the observational program, reduction process, and plate measurement for the catalog are examined.
A development of double star astronomy after Hipparcos
Lampens, P.; Dommanget, J.
Now that the HIPPARCOS satellite safely revolves on his 'degraded' orbit - after the exploit of the ESA technicians to rescue it from the faulty ignition of its apogeum boost motor - and regularly provides the information needed for reaching the initial aim of the project, one may turn to examine the possible applications of the finalHipparcos Cat…