Search Publications
Intermittent behavior in the transition region and the low corona of the quiet Sun
Vial, J. -C.; Patsourakos, S.
We present an analysis of light-curves obtained in the O IV and Ne VIII transition region and low corona lines, that were simultaneously recorded in a quiet Sun region by SUMER/SOHO. By using the flatness spectrum of the observed light-curves we searched for intermittency signatures. It was found that a significant proportion of points in the obse…
A photometric study of the two poorly known northern open clusters NGC 133 and NGC 1348
Carraro, G.
We present CCD UBVI observations obtained in the field of the previously unstudied northern open clusters NGC 133 and NGC 1348. We argue that NGC 133 is a heavily contaminated cluster, for which we identify 13 candidate members down to V=14.50 mag on the basis of the position in the two-color Diagram. Membership has been checked against proper mot…
Thick disk and old disk carbon-rich giants in the Sun vicinity
Bergeat, J.; Knapik, A.; Rutily, B.
Making use of the HIPPARCOS data and refining a previous study of the space distribution of the carbon-rich giant stars located in the vicinity of the Sun (Paper I), we fully investigate their space distributions and space velocities on the basis of our photometric grouping (CVi i.e. carbon variable stars with i=1 to 7; HCj i.e. hot carbon stars w…
The ISO Galactic metallicity gradient revisited
Morisset, C.; Sternberg, A.; Giveon, U.
Two independent groups (Giveon et al. \cite{giveon}; Martín-Hernández et al. \cite{martin}) have recently investigated the Galactic metallicty gradient as probed by ISO observations of mid-infrared emission-lines from HII regions. We show that the different gradients inferred by the two groups are due to differing source selection and differing ex…
First XMM-Newton observations of the globular cluster M 22
Webb, N. A.; Barret, D.; Gendre, B.
We have examined preliminary data of the globular cluster, M 22, from the EPIC MOS detectors on board XMM-Newton. We have detected 27 X-ray sources within the centre of the field of view, 24 of which are new detections. Three sources were found within the core of the cluster. From spectral analysis of the X-ray sources, it is possible that the obj…
Determination of limits on disc masses around six pulsars at 15 and 90 µm
Pantin, E.; Sauvage, M.; Naylor, T. +3 more
We have searched for evidence of emission at 15 µm with ISOCAM and at 90 µm with ISOPHOT from dust orbiting six nearby pulsars, both in binaries and in isolation, located at distances between about 100 to 1000 pc. No emission was detected at any of the pulsar positions, and for the nearest pulsar J0108-1431 the 3 sigma ma upper limits …
Metallicity and radial velocity of the second parameter globular cluster Terzan 1 in the galactic bulge
Bica, E.; Barbuy, B.; Ortolani, S. +3 more
Terzan 1 is the globular cluster with closest projection relative to the Galactic center. We report radial velocities and metallicities of 17 stars in order to investigate their membership in the cluster. From the 11 probable members of Terzan 1, a radial velocity of vr = 114 +/- 14 km s-1 is obtained. For this sample an inte…
The EIT coil-like structure in the March 20, 2000 eruptive prominence
Karlický, M.; Šimberová, S.
The evolution of the March 20, 2000 prominence eruption observed in the 195 Å(EIT/SOHO), Hα , (MDI/SOHO), 1-3 GHz radio and hard X-ray (BATSE) was analyzed. A unique EIT coil-like structure with a hot core, indicating an electric current, was observed at the beginning of the prominence eruption. This structure with about 5 turns was associated wit…
Chemically distinct nuclei and circumnuclear rings in lenticular galaxies NGC 4429 and NGC 7013
Sil'chenko, O. K.; Afanasiev, V. L.
The central regions of the regular lenticular galaxies NGC 4429 and NGC 7013 have been studied with the Multi-Pupil Field (Fiber) Spectrograph (MPFS) of the 6 m telescope of the Special Astrophysical Observatory RAS (Nizhnij Arkhyz, Russia) in two spectral ranges, the blue one including the strong absorption lines Mg I and Fe I and the red one inc…
Astrometry of the stellar image of U Her amplified by the circumstellar 22 GHz water masers
Vlemmings, W. H. T.; van Langevelde, H. J.; Diamond, P. J.
The 22 GHz H2O masers in the circumstellar envelope of the Mira variable star U Her have been observed with MERLIN using a phase referencing technique to determine accurate astrometric positions. The positions were compared with the optical positions obtained with the Hipparcos satellite to an accuracy of 18 mas. The absolute radio posi…