Search Publications
Jovicentric latitude effect on the bKOM radio emission observed by Ulysses/URAP
MacDowall, R. J.; Lecacheux, A.; Barrow, C. H.
During 1994 and into 1996, Ulysses was at distances of 5 AU or more from Jupiter and travelling from south to north of the ecliptic plane. At these distances, the jovian broadband radio emission (bKOM) was only received occasionally by the Unified Radio and Plasma Experiment (URAP) on board the Ulysses spacecraft. The signals were generally weak a…
A close look into an intermediate redshift galaxy using STIS
Pasquali, A.; de Mello, D. F.
We present a detailed view of a galaxy at z=0.4 which is part of a large database of intermediate redshifts using high resolution images. We used the STIS parallel images and spectra to identify the object and obtain the redshift. The high resolution STIS image (0.05'') enabled us to analyse the internal structures of this galaxy. A bar along the …
Dopplershifts in the solar transition region
Vial, J. -C.; Gontikakis, C.; Alissandrakis, C. E. +2 more
We study the dynamics of the quiet sun transition region, using observations obtained with the SOHO CDS/NIS and SUMER spectrographs. We examine the morphology of the network as a function of temperature and we compare the intensity features with those of the dopplergrams. The velocity distributions have a different behaviour for the bright feature…
XMM-Newton observations of the BL Lac MS 0737+7441
Boller, Th.; Brinkmann, W.; Keil, R. +5 more
We report on the XMM-Newton observations of the BL Lac object MS 0737.9+7441 during the performance verification phase. A simple power-law fit provides an adequate description of the integrated spectrum in the 0.2-10 keV energy band. The photon index is slightly steeper in the EPIC pn data with Gamma = (2.38 +/- 0.01) compared to the EPIC MOS data…
Research Note Nice Observatory CCD measurements of visual double stars (3rd series)
Gili, R.; Salaman, M.; Morlet, G.
We present the measurements of 58 visual double stars made in 1999 and 2000 with the 50 cm refractor of the Nice Observatory and attached CCD camera, using an algorithm based on the adjustment of a tridimensional mathematical surface (Table 1). 2 new binaries discovered by Hipparcos were measured.
V505 Mon - An early-type binary with a disk
Chochol, D.; Drechsel, H.; Lorenz, R. +4 more
New spectra of the eclipsing binary V505 Mon (usually classified as B5 Ib) were obtained in the optical and UV regions. Only spectral lines of one component are visible, with K = 93 km s-1. According to arguments based on the extent of the disk the mass ratio might be about 0.30. The star with the visible spectral lines would then have …
Stellar and circumstellar evolution of long period variable stars
Luri, X.; Mennessier, M. O.
In a first paper, HIPPARCOS astrometric and kinematic data were used to calibrate both infrared K and IRAS luminosities at the same time as kinematic parameters of Long Period Variable stars (LPVs). Individual estimated absolute magnitudes and a probabilistic assignation to galactic populations were deduced from these calibrations for each LPV of …
Radial velocities of giant M stars near the ecliptic
Bettoni, D.; Galletta, G.
A search dedicated to the identification of new, dwarf and cold stars close to the Sun has allowed us to measure the radial velocities of a set of stars of late spectral type. The stars selected were M-type stars present in the Hipparcos Input Catalogue located in a strip of +/-20° around the Ecliptic and observables from La Silla. Our inal set co…
Noise reduction in helioseismic power spectra\ by non-orthogonal wavelets
Solanki, S. K.; Kosovichev, A. G.; Régulo, C. +1 more
We present a method to reduce noise in helioseismic power spectra using a non-orthogonal wavelet transform based on quadratic spline functions. The quality of our method is tested by applying it to artificially generated time-series approximating solar p-modes. The mode frequencies and line widths obtained from least-squares fits to the smoothed s…
What can HST-GHRS Fe II observations of α Orionis (M2 Iab) tell us about short-period heating?
Cuntz, M.; Harper, G. M.; Bennett, P. D.
Cuntz (\cite{Cuntz97}) suggested that apparent velocity shifts in Fe II emission lines observed in Betelgeuse (alpha Orionis: M2 Iab) indicate that non-magnetic wave modes are relevant for the heating and dynamics of alpha Ori's chromosphere. This claim was based on the similarity of computed stochastic velocities in 1-D short-period acoustic wave…