Search Publications
Kinematics and CMD of the globular cluster NGC 4147
Chen, L.; Geffert, M.; Wang, J. J. +2 more
Astrometry and BVRI CCD photometry of 115 stars down to B=17.6 in the region of about 11' x 11' around the globular cluster NGC 4147 was performed. In the astrometric reduction, three earlier epoch plates taken at Sheshan, Shanghai, China, in 1958 and four recent epoch B-passband CCD frames taken at Kavalur, India, were used.…
A combined approach for object detection and deconvolution
Valtchanov, I.; Starck, J. -L.; Bijaoui, A. +1 more
The Multiscale Vision Model is a recent object detection method, based on the wavelet transform. It allows us to extract all objects contained in an image, whatever their size or their shape. From each extracted object, information concerning flux or shape can easily be determined. We show that such an approach can be combined with deconvolution, …
Variable HST guide stars (I)
Zwintz, K.; Frandsen, S.; Kuschnig, R. +4 more
We have performed time series analyses on more than 4500 sets of Hubble Space Telescope (HST) Fine Guidance Sensor (FGS) data, obtained from about 3600 guide stars in the period from August 1992 to December 1995. We discuss here a subset of 20 stars that were found to be variable at a high confidence level. This subset contains all definite variab…
A proper motion study of the globular cluster M 10
Chen, L.; Geffert, M.; Wang, J. J. +2 more
We present the first proper motion study of M 10 (NGC 6254). Absolute proper motions of about 532 stars in the field of the globular cluster M 10 were determined with respect to Hipparcos and ACT reference stars. In addition to photographic plates of Bonn and Shanghai also wide field CCD observations as second epoch plates were used. The wide fiel…
CCD measurements of visual double stars made with the 50 cm refractor of the Nice Observatory (2nd series)
Gili, R.; Salaman, M.; Morlet, G.
We present the measurements of 65 visual double stars made in 1998 with the 50 cm refractor of the Nice Observatory (Table 1). A CCD camera was attached to this refractor. 6 new binaries discovered by Hipparcos have been measured. The algorithm used for these measurements is based on the adjustment of a tridimensional mathematical surface. Table 1…
A catalogue of galaxies in the HDF-South: Photometry and structural parameters
Chincarini, G.; Saracco, P.; Volonteri, M.
We describe the construction of a catalogue of galaxies in the optical field of the Hubble Deep Field South. The HDF-S observations produced WFPC2 images in U, B, V, and I, the version 1 data have been made public on 23 November 1999. The effective field of view is 4.38 arcmin2, and the 5sigma limiting magnitudes (in a FWHM aperture) ar…
Magnitudes absolues des étoiles standards MK des types G à M à partir des parallaxes Hipparcos. The absolute magnitudes of the G to M type MK standards from the Hipparcos parallaxes
Jaschek, C.; Ginestet, N.; Carquillat, J. M.
We analyse a sample of about 500 MK standards of cool spectral types (G to M) for to compare the visual absolute magnitudes obtained from both Hipparcos data and Schmidt-Kaler calibrations. Our purpose is to validate our spectroscopic work \cite[(Ginestet et al. 1997, 1999)]{G97} on stars with composite spectra with the help of Hipparcos data. Con…
The U.S. Naval Observatory pole-to-pole catalog: W2J00
Rafferty, T. J.; Holdenried, E. R.
Between the years 1985 and 1996 the U.S. Naval Observatory (USNO), using two transit circles, one located in Washington, DC (U.S.A.) and the other in Blenheim, New Zealand, conducted an ambitious program of absolute observations of positions of celestial objects completely covering both hemispheres. Over 737 000 individual observations were made, …
Contribution à l'étude des binaires des types F, G, K, M. VIII. HD 195850 et HD 201193, binaires spectroscopiques à raies doubles Contribution to the study of F, G, K, M binaries. VIII. HD 195850 and HD 201193, double-lined spectroscopic binaries
Ginestet, N.; Carquillat, J. M.
Radial-velocity observations of the double-lined spectroscopic binaries HD 195850 and HD 201193 have been carried out at the Observatoire de Haute-Provence with the CORAVEL instrument in order to determine their orbital elements. They are as follows HD 195850: P = 37.94106 days; T = 2444872.24 HJD; omega = 111o 5 ; e = 0.185; K_1 = 34.1…
Location of the activity responsible for the appearance of coronal mass ejections and the sites of their ejection from the solar surface.
Shilova, N. S.
The white-light films of coronal mass ejections for April - May, 1998 (SOHO LASCO C2, C3), retrieved from Internet, are considered. The positions of active regions on visible and back sides of the Sun for each day are studied. It is shown that a region of large flare can be localized at a distance not less than the solar radius from the place wher…