Search Publications
Radial velocities of HIPPARCOS southern B8-F2 type stars
Gerbaldi, M.; Faraggiana, R.; Grenier, S. +5 more
Radial velocities have been determined for a sample of B8-F2 type stars observed by the Hipparcos satellite. Observations were obtained within the framework of an ESO key-program. Radial velocities have been measured using a cross-correlation method, the templates being a grid of synthetic spectra. The obtained precision depends on effective tempe…
Classification of EUV stellar sources detected by the ROSAT WFC. I. Photometric and radial velocity studies
Tagliaferri, G.; Pallavicini, R.; Messina, S. +2 more
We present the results of high-precision UBV(RI)_c photometric observations and of spectroscopic radial velocity measurements obtained at the European Southern Observatory for a sample of 51 cool stars detected in the EUV by the ROSAT Wide Field Camera (WFC). Using also recent results from HIPPARCOS, we infer spectral types and investigate the sin…
Faint source detection in ISOCAM images
Aussel, H.; Elbaz, D.; Cesarsky, C. +2 more
We present a tool adapted to the detection of faint mid-infrared sources within ISOCAM mosaics. This tool is based on a wavelet analysis which allows us to discriminate sources from cosmic ray impacts at the very limit of the instrument, four orders of magnitudes below IRAS. It is called PRETI for Pattern REcognition Technique for ISOCAM data, bec…
Predicted HST FOC and broad band colours for young and intermediate simple stellar populations.
Romaniello, M.; Castellani, V.; Brocato, E. +1 more
This paper presents theoretical HST and broad band colours from population synthesis models based on an homogeneous set of stellar evolutionary tracks as computed under canonical (no overshooting) assumptions, covering the range of cluster ages from t = 8 Myr to t = 5 Gyr for three different metallicities (Z=0.02, 0.006, and 0.001). Statistical fl…
The EXOSAT medium-energy slew survey catalog
Parmar, A. N.; Pollock, A. M. T.; Taylor, B. G. +4 more
We present a catalog of X-ray sources observed during slew maneuvers by the Medium Energy Detector Array onboard the EXOSAT Observatory. The EXOSAT Medium Energy slew-survey catalog (EXMS) provides a unique record of the 1-8 keV X-ray sky between 1983 and 1986. 98% of the sky was observed, with 85% receiving an exposure of >60 s. 1210 sources w…
IC 348 proper motion study from digitised Schmidt plates
Preibisch, T.; Zinnecker, H.; Meusinger, H. +6 more
A new proper motion study for about 1400 stars with R < 18 mag in a one square degree region around the young open cluster IC 348 based on Schmidt plates is presented. With an overall accuracy of about 3 mas/yr (2.5 mas/yr, respectively for all stars with R < 17 mag) we have obtained membership probabilities dividing our sample into three gr…
The Bordeaux and Valinhos CCD meridian circles
Teixeira, R.; Colin, J.; Mazurier, J. M. +14 more
A first CCD 512x 512 camera working in scan mode (declination field 14') was mounted in 1994 on the Bordeaux CCD meridian circle. After a testing period, this camera was installed on the Valinhos CCD meridian circle (near S\ ao Paulo, Brazil), as part of a collaboration between Bordeaux Observatory and the Instituto Astronomico e Geofisico of S\ a…
A search for rapid oscillations in chemically peculiar A-type stars
Handler, G.; Paunzen, E.
In 1995 we initiated a Northern Hemisphere survey for rapidly oscillating Ap stars. This paper presents the results including one new roAp star (HD 122970), the confirmation of rapid oscillations of HD 99563 and apparent null results for other stars. Using Hipparcos data a statistical analysis of the absolute magnitudes and galactic distributions …
Search for reference A0 dwarf stars: Masses and luminosities revisited with HIPPARCOS parallaxes
Gerbaldi, M.; Faraggiana, R.; Grenier, S. +3 more
Hipparcos data for 71 nearby dwarf A0 stars were combined with other data, in particular with high resolution spectra to establish the HR diagram in this temperature range. Almost 30% of unknown binaries were detected and discarded before establishing the cal M-L relation for bright A0 V field stars. The relationship derived for these single stars…
Characterization of variable stars by robust wave variograms: an application to HIPPARCOS mission
Eyer, L.; Genton, M. G.
Variogram analysis is applied to time series of variable stars. This method allows to characterize time-scales of varying signals. It is well suited for periodic and pseudo-periodic signals. The aspects of robustness, bin positions and bin widths for the variogram estimator are assessed, evaluated with the help of simulations and adapted to the Hi…