Search for associations containing young stars. III- Ages and Li abundances (2009)
Da Silva, L., Torres, C. A. O., Quast, G. R., Melo, C. H. F., Sterzik, M.
Our study is a follow-up of the SACY project, an extended survey in the Southern Hemisphere targeted to search for young nearby associations. Nine associations have either been newly identified, or...
Testing planet formation theories with Giant stars (2008)
Pasquini, Luca, Doellinger, M. P., Hatzes, A., Setiawan, J., Girardi, L., Da Silva, L., ...
Planet searches around evolved giant stars are bringing new insights to planet formation theories by virtue of the broader stellar mass range of the host stars compared to the solar-type stars that...
Planets around active stars (2008)
Setiwan, J., Weise, P., Henning, Th., Hatzes, A. P., Pasquini, L., Da Silva, L., ...
Si and Ca abundances of a selected sample of evolved stars (2008)
Da Silva, L., Girardi, L., Pasquini, L., De Medeiros, R., Setiawan, J., Döllinger, M., ...
Metallicity and age of selected G-K giants (2008)
Pasquini, Luca, Döllinger, M., Setiawan, J., Hatzes, A., Girardi, L., Da Silva, L., ...
Testing planet formation theories with giant stars (2008)
Pasquini, Luca, Döllinger, M. P., Hatzes, A., Setiawan, J., Girardi, L., Da Silva, L., ...
Testing planet formation theories with giant stars (2008)
Pasquini, Luca, Döllinger, M. P., Hatzes, A., Setiawan, J., Girardi, L., Da Silva, L., ...
Planet searches around evolved giant stars are bringing new insights to planet formation theories by virtue of the broader stellar mass range of the host stars compared to the solar-type stars that...
Planets around giant stars (2008)
Hatzes, A. P., Döllinger, M., Pasquini, L., Setiawan, J., Girardi, L., Da Silva, L.
Not Available
Evolved stars hint to an external origin of enhanced metallicity in planet-hosting stars (2007)
Pasquini, L., Doellinger, M. P., Weiss, A., Girardi, L., Chavero, C., Hatzes, A. P., ...
Exo-planets are preferentially found around high metallicity main sequence stars. We aim at investigating whether evolved stars share this property, and what this tells about planet formation....
Biazzo, K., Pasquini, L., Girardi, L., Frasca, A., Da Silva, L., Setiawan, J., ...
We test our capability of deriving stellar physical parameters of giant stars by analysing a sample of field stars and the well studied open cluster IC 4651 with different spectroscopic methods. The...
Planets around active stars (2007)
Setiawan, J., Weise, P., Henning, Th., Hatzes, A. P., Pasquini, L., Da Silva, L., ...
We present the results of radial velocity measurements of two samples of active stars. The first sample contains field G and K giants across the Red Giant Branch, whereas the second sample consists...
Physical parameters of evolved stars in clusters and in the field from line-depth ratios (2007)
Biazzo, K., Pasquini, L., Frasca, A., Da Silva, L., Girardi, L., Hatzes, A. P., ...
We present a high-resolution spectroscopic analysis of two samples of evolved stars selected in the field and in the intermediate-age open cluster IC 4651, for which detailed measurements of chemical...
Abundance analysis of barium and mild barium stars (2007)
High signal to noise, high resolution spectra were obtained for a sample of normal, mild barium, and barium giants. Atmospheric parameters were determined from the FeI and FeII lines. Abundances for...
Evolved stars suggest an external origin of the enhanced metallicity in planet-hosting stars (2007)
Pasquini, L., Döllinger, M. P., Weiss, A., Girardi, L., Chavero, C., Hatzes, A. P., ...
Evolved stars suggest an external origin of the enhanced metallicity in planet-hosting stars (2007)
Pasquini, L., Döllinger, M. P., Weiss, A., Girardi, L., Chavero, C., Hatzes, A. P., ...
Aims. Exo-planets are preferentially found around high metallicity main sequence stars. We investigate whether evolved stars share this property, and its implications for planet formation. Methods:...
Biazzo, K., Pasquini, L., Girardi, L., Frasca, A., Da Silva, L., Setiawan, J., ...
Aims.We test our capability of deriving stellar physical parameters of giant stars by analysing a sample of field stars and the well studied open cluster IC 4651 with different spectroscopic methods....
Demystifying basal-like breast carcinomas (2007)
Da Silva, L., Clarke, C., Lakhani, S.R.
"Basal'' breast cancers are dominating the breast research literature at present and pathologists are under increasing pressure to evaluate for such a phenotype by their surgical and oncological...
Demystifying basal-like breast carcinomas (2007)
Da Silva, L., Clarke, C., Lakhani, S.R.
"Basal'' breast cancers are dominating the breast research literature at present and pathologists are under increasing pressure to evaluate for such a phenotype by their surgical and oncological...
Search for Associations Containing Young stars (SACY): I. Sample & Searching Method (2006)
Torres, C. A. O., Quast, G. R., Da Silva, L., Melo, C. H. F., Sterzik, M.
We report results from a high-resolution optical spectroscopic survey aimed to search for nearby young associations and young stars among optical counterparts of ROSAT All-Sky Survey X-ray sources in...
A catalog of rotational and radial velocities for evolved stars. IV. Metal-poor stars (2006)
De Medeiros, J. R., Silva, J. R. P., Nascimento, J. D. Jr. Do, Martins, B. L. Canto, Da Silva, L., Melo, C., ...
The present paper describes the first results of an observational program intended to refine and extend the existing vsini measurements of metal-poor stars, with anemphasis on field evolved stars....
Basic physical parameters of a selected sample of evolved stars (2006)
Da Silva, L., Girardi, L., Pasquini, L., Setiawan, J., De Medeiros, J. R., ...
We present the detailed spectroscopic analysis of 72 evolved stars, including the [Fe/H] determination for the whole sample. These metallicities, together with the Teff values and the absolute V...
Radial velocity variations of G and K giants (2006)
Döllinger, M. P., Pasquini, L., Hatzes, A., Weiss, A., Setiawan, J., Da Silva, L., ...
Basic physical parameters of a selected sample of evolved stars (2006)
Da Silva, L., Girardi, L., Pasquini, L., Setiawan, J., De Medeiros, J. R., ...
Radial velocity variations of G and K giants (2006)
Döellinger, M. P., Pasquini, L., Hatzes, A., Weiss, A., Setiawan, J., Da Silva, L., ...
G and K giants are a new class of radial velocity (RV) variables. In order to reveal the reasons of this variability we started in February 2004 a program to observe a northern sample of 62 K giants...
Basic physical parameters of a selected sample of evolved stars (2006)
Da Silva, L., Girardi, L., Pasquini, L., Setiawan, J., De Medeiros, J. R., ...
We present the detailed spectroscopic analysis of 72 evolved stars, which were previously studied for accurate radial velocity variations. Using one Hyades giant and another well studied star as the...
Asteroseismology of K Giants (2006)
Di Mauro, M. P., Cardini, D., D'Antona, F., Weiss, A., Döllinger, M. P., Pasquini, L., ...
The Spectral Energy Distribution of the Seyfert galaxy Ton S180 (2005)
Turner, T. J., Romano, P., Kraemer, S. B., George, I. M., Yaqoob, T., Crenshaw, D. M., ...
We present spectral results from a multi-satellite, broad-band campaign on the Narrow-line Seyfert 1 galaxy Ton S180 performed at the end of 1999. We discuss the spectral-energy distribution of the...
Del Peloso, E. F., Cunha, K., Da Silva, L.
We present Mn, Co and Eu abundances for a sample of 20 disk F and G dwarfs and subgiants with metallicities in the range -0.8
The age of the Galactic thin disk from Th/Eu nucleocosmochronology III. Extended sample (2005)
Del Peloso, E. F., Da Silva, L., Arany-Prado, L. I.
The first determination of the age of the Galactic thin disk from Th/Eu nucleocosmochronology was accomplished by us in Papers I and II. The present work aimed at reducing the age uncertainty by...
A substellar companion around the intermediate-mass giant star HD 11977 (2005)
Setiawan, J., Rodmann, J., Da Silva, L., Hatzes, A. P., Pasquini, L., ...
We report the discovery of a substellar companion to the intermediate-mass star HD 11977 (G5 III). Radial velocities of this star have been monitored for five years with FEROS at the 1.52-m ESO and...
Atmospheric parameters of a sample of giant stars with accurate radial velocity variations (2005)
Da Silva, L., Girardi, L., Pasquini, L., Döllinger, M., De Medeiros, R., Setiawan, J., ...
A substellar companion around the intermediate-mass giant star HD 11977 (2005)
Setiawan, J., Rodmann, J., Da Silva, L., Hatzes, A. P., Pasquini, L., ...
We report the discovery of a substellar companion to the intermediate-mass star HD 11977 (G5 III). Radial velocities of this star have been monitored for five years with FEROS at the 1.52-m ESO and...
Del Peloso, E. F., Da Silva, L.
The purpose of this work is to resume investigation of Galactic thin disk dating using nucleocosmochronology with Th/Eu stellar abundance ratios, a theme absent from the literature since 1990. A...
The age of the Galactic thin disk from Th/Eu nucleocosmochronology II. Chronological analysis (2004)
Del Peloso, E. F., Da Silva, L., Arany-Prado, L. I.
The purpose of this work is to resume investigation of Galactic thin disk dating using nucleocosmochronology with Th/Eu stellar abundance ratios, a theme absent from the literature since 1990....
Setiawan, J., Pasquini, L., Da Silva, L., Hatzes, A. P., Girardi, L., ...
We present the results of our radial velocity (RV) measurements of G and K giants, concentrating on the presence of multiple systems in our sample. Eighty-three giants have been observed for 2.5...
Binaries from FEROS radial velocity survey (2004)
Setiawan, J., Da Silva, L., Pasquini, L., Hatzes, A. P., Girardi, L., ...
High pressures generated by laser driven shocks: applications to planetary physics (2004)
Koenig, M, Henry, E, Huser, G, Benuzzi-Mounaix, A, Faral, B, Martinolli, E, ...
Nanoengineered Astronomical Optics (2003)
Borra, E. F., Ritcey, A. M., Bergamasco, R., Laird, P., Gingras, J., Dallaire, M., ...
We describe a technology for the fabrication of inexpensive and versatile mirrors through the use of a new type of nanoengineered optical material composed by the spreading of a self-assembling...
Evidence of a sub-stellar companion around HD 47536 (2003)
Setiawan, J., Hatzes, A. P., Pasquini, L., Naef, D., Da Silva, L., ...
We report evidence of a low-mass companion around the K1III giant star HD 47536. This star belongs to our sample of 83 subgiant and giant stars studied for their radial velocity variations using the...
Precise radial velocity measurements of G and K giants. First results (2003)
Setiawan, J., Pasquini, L., Da Silva, L., Hatzes, A.
We present the first results of our precise radial velocity (RV) measurements of G and K giants. A number of stars from our list of 80 targets have been observed for 14 months using the fibre-fed...
Torres, C. A. O., Quast, G. R., Da Silva, L., Melo, C. H. F.
The scientific goal of the SACY (Search for Associations Containing Young-stars) project is to identify eventual associations of stars younger than the Local Association, spread among the optical...
Postcard size colour photograph
Books on shelves in Library, University of Pretoria (2002)
Shelves with books in library.
Exhibition in library of models by architecture students, University of Pretoria (2002)
Exhibition in library of models by architecture students.
Postcard size colour photograph
Books on shelves in Library, University of Pretoria (2002)
Shelves with books in library.
Exhibition in library of models by architecture students, University of Pretoria (2002)
Exhibition in library of models by architecture students.
The tidal effects on the lithium abundance of binary systems with giant component (2001)
Costa, J. M., Da Silva, L., De Medeiros, J. R.
We analise the behavior of lithium abundance as a function of effective temperature, projected rotational velocity, orbital period and eccentricity for a sample of 68 binary systems with giant...
The Spectral Energy Distribution of the Seyfert galaxy Ton S180 (2001)
Turner, T. J., Romano, P., Kraemer, S. B., George, I. M., Yaqoob, T., Crenshaw, D. M., ...
We present spectral results from a multi-satellite, broad-band campaign on the Narrow-line Seyfert 1 galaxy Ton S180 performed at the end of 1999. We discuss the spectral-energy distribution of the...
Da Silva, L., Jilinski, E., Torres, C. A. O., Quast, G.
Since the eighties we have begun, in Brazil, a search for Post-T Tauri stars. Here we describe the main steps of this research that resulted in the discovery of the nearby TW Hya and Horologium...
The Great Austral Nearby Young Association (2001)
Torres, C. A. O., Quast, G. R., Da Silva, L., Melo, C. H. F.
Observing ROSAT sources in an area covering $\sim$30% of the Southern Hemisphere, we found evidences for a great nearby association (GAYA), comprising the proposed associations of Horologium (HorA)...
The Extended R CrA Young Association (2001)
Quast, G. R., Torres, C. A. O., Da Silva, L., Drake, N.
Observing ROSAT sources in an area covering ~30% of the Southern Hemisphere, including the R CrA Association, we found evidences that this nearby association may be much larger than previously...
The Spectral Energy Distribution of the Seyfert galaxy Ton S180 (2001)
Turner, T. J., Romano, P., Kraemer, S. B., George, I. M., Yaqoob, T., Crenshaw, D. M., ...
We present spectral results from a multi-satellite, broad-band campaign on the Narrow-line Seyfert 1 galaxy Ton S180 performed at the end of 1999. We discuss the spectral-energy distribution of the...
The Spectral Energy Distribution of the Seyfert galaxy Ton S180 (2001)
Turner, T. J., Romano, P., Kraemer, S. B., George, I. M., Yaqoob, T., Crenshaw, D. M., ...
We present spectral results from a multi-satellite, broad-band campaign on the Narrow-line Seyfert 1 galaxy Ton S180 performed at the end of 1999. We discuss the spectral-energy distribution of the...
Copper and Barium Abundances in the Ursa Major Moving Group (1999)
We present Cu and Ba abundances for 7 G-K dwarf stars, members of the solar-metallicity, 0.3 Gyr old Ursa Major Moving Group. All analyzed member stars show [Ba/Fe] excesses of +0.3-plus, associated...
On a Rapid Lithium Enrichment and Depletion of K Giant Stars (1997)
Drake, N. A., Da Silva, L., Torres, C. A. O., Martin, E. L.
A model scenario has recently been introduced to explain the presence of very strong Li lines in the spectra of some low mass K giant stars (de la Reza et al. 1996). In this scenario all ordinary, Li...
SPALLATION UNDER THE ACTION OF A LASER INDUCED SHOCK WAVE (1988)
Cottet, F., Ng, A., Da Silva, L., Marty, L.
The conditions of laser-driven shock wave loading leads to study the dynamic fracture in an unusual range of stress and strain rates : 0.2-2 Mbar and more than 107s-1. A cumulative damage criteria...
SPALLATION UNDER THE ACTION OF A LASER INDUCED SHOCK WAVE (1988)
Cottet, F., Ng, A., Da Silva, L., Marty, L.
The conditions of laser-driven shock wave loading leads to study the dynamic fracture in an unusual range of stress and strain rates : 0.2-2 Mbar and more than 107s-1. A cumulative damage criteria...
SPALLATION UNDER THE ACTION OF A LASER INDUCED SHOCK WAVE (1988)
Cottet, F., Ng, A., Da Silva, L., Marty, L.
The conditions of laser-driven shock wave loading leads to study the dynamic fracture in an unusual range of stress and strain rates : 0.2-2 Mbar and more than 107s-1. A cumulative damage criteria...