Search results for "STELLA"
showing 10 items of 1995 documents
Post-AGB candidates in LMC and SMC SALT spectra
2020
We selected a sample of post-AGB candidates in the Magellanic Clouds on the basis of their near- and mid-infrared colour characteristics. Fifteen of the most optically bright post-AGB candidates were observed with the South African Large Telescope in order to determine their stellar parameters and thus to validate or discriminate their nature as post-AGB objects in the Magellanic Clouds. The spectral types of absorption-line objects were estimated according to the MK classification, and effective temperatures were obtained by means of stellar atmosphere modelling. Emission-line objects were classified on the basis of the fluxes of the emission lines and the presence of the continuum. Out of…
Catching the radio flare in CTA 102
2013
Very Long Baseline Interferometry (VLBI) observations can resolve the radio structure of active galactic nuclei (AGN) and provide estimates of the structural and kinematic characteristics on parsec-scales in their jets. The changes in the kinematics of the observed jet features can be used to study the physical conditions in the innermost regions of these sources. We performed multifrequency multiepoch Very Long Baseline Array (VLBA) observations of the blazar CTA102 during its 2006 radio flare, the strongest ever reported for this source. These observations provide an excellent opportunity to investigate the evolution of the physical properties of blazars, especially during these flaring e…
The Gaia-ESO Survey: The inner disk, intermediate-age open cluster Trumpler 23
2017
Full list of authors: Overbeek, J. C.; Friel, E. D.; Donati, P.; Smiljanic, R.; Jacobson, H. R.; Hatzidimitriou, D.; Held, E. V.; Magrini, L.; Bragaglia, A.; Randich, S.; Vallenari, A.; Cantat-Gaudin, T.; Tautvaišienė, G.; Jiménez-Esteban, F.; Frasca, A.; Geisler, D.; Villanova, S.; Tang, B.; Muñoz, C.; Marconi, G. Carraro, G.; San Roman, I.; Drazdauskas, A.; Ženovienė, R.; Gilmore, G.; Jeffries, R. D.; Flaccomio, E.; Pancino, E.; Bayo, A.; Costado, M. T.; Damiani, F.; Jofré, P.; Monaco, L.; Prisinzano, L.; Sousa, S. G.; Zaggia, S.
Catalanes, valencianos y mallorquines en la Ortografía de la lengua castellana (1831) de J. del Castillo y Mayone
2019
Análisis de la obra Ortografía de la lengua castellana para uso de toda clase de personas: con reglas particulares para los catalanes, valencianos y mallorquines deducidas de su propio idioma y observaciones sobre los escollos en que peligran y pueden evitar, en la Imprenta de Corchs, Barcelona, 1831 de Joaquín del Castillo y Mayone. Es una obra general sobre la ortografía de la lengua castellana dirigida y arreglada especialmente para los catalanohablantes, lo que supone una novedad en el panorama de las ortografías peninsulares de la primera mitad del siglo XIX. Este trabajo presenta todas las características de la ortografía contrastiva que contiene, los aspectos historiográficos e ideol…
STUDIES OF VARIABILITY IN PROTO-PLANETARY NEBULAE. II. LIGHT AND VELOCITY CURVE ANALYSES OF IRAS 22272+5435 AND 22223+4327
2013
We have carried out a detailed observational study of the light, color, and velocity variations of two bright, carbon-rich proto-planetary nebulae, IRAS 22223+4327 and 22272+5435. The light curves are based upon our observations from 1994 to 2011, together with published data by Arkhipova and collaborators. They each display four significant periods, with primary periods for IRAS 22223+4327 and 22272+5435 being 90 and 132 days, respectively. For each of them, the ratio of secondary to primary period is 0.95, a value much different from that found in Cepheids, but which may be characteristic of post-asymptotic giant branch (AGB) stars. Fewer significant periods are found in the smaller radia…
Pulsating B and Be stars in the Small Magellanic Cloud
2008
Context: Stellar pulsations in main-sequence B-type stars are driven by the kappa-mechanism due to the Fe-group opacity bump. The current models do not predict the presence of instability strips in the B spectral domain at very low metallicities. As the metallicity of the SMC is lower than Z=0.005, it constitutes a very suitable object to test these predictions. Aims: The main objective is to investigate the existence of B-type pulsators at low metallicities, searching for short-term periodic variability in absorption-line B and Be stars in the SMC. The analysis has been performed in a sample of 313 B and Be stars with fundamental astrophysical parameters accurately determined from high-res…
Paesaggi minerari in Sicilia: da residuo a risorsa. Strategie e progetto di recupero per il parco minerario Floristella-Grottacalda.
La tesi indaga, attraverso una serie di riflessioni critiche e progettuali, il ruolo che le aree minerarie possono avere nella definizione di nuovi paesaggi. Lo studio si concentra sull'industria dello zolfo in Sicilia, sviluppatasi dalla fine del Settecento e definitivamente dismessa negli anni Ottanta del secolo scorso, con ripercussioni negative sul fronte economico, sociale, ambientale e paesaggistico. La trasformazione delle aree minerarie siciliane richiede una cultura progettuale tale da mettere in relazione architettura, ingegneria, infrastrutture, comunità locali e modelli socio-economici, nel tentativo di esplorare le profonde trasformazioni che questi paesaggi hanno attraversato.…
Rotational effects on the oscillation frequencies of newly born proto-neutron stars
2003
In this paper we study the effects of rotation on the frequencies of the quasi-normal modes of a proto-neutron star (PNS) born in a gravitational collapse during the first minute of life. Our analysis starts a few tenths of seconds after the PNS formation, when the stellar evolution can be described by a sequence of equilibrium configurations. We use the evolutionary models developed by Pons et al. (1999; 2001) that describe how a non rotating star cools down and contracts while neutrino diffusion and thermalization processes dominate the stellar dynamics. For assigned values of the evolution time, we set the star into slow rotation and integrate the equations of stellar perturbations in th…
La Reggia di Venaria Reale in Italy and Palacio Real de Aranjuez in Spain: history, restoration and significance, comparative study between Two Royal…
2017
La investigación relaciona dos sitios reales, La Reggia di Venaria Reale en Italia y el Palacio Real de Aranjuez en España, confrontando su desarrollo histórico y arquitectónico, las obras de restauración llevadas a cabo, los criterios para su inclusión en la Lista de Patrimonio Mundial y su uso hoy en día como museos. El estudio comparativo muestra cómo ambos palacios se usaban inicialmente como residencias de caza en lugares con abundancia de agua y pesca. Además, los dos están ubicados cerca de las capitales políticas de su tiempo; esto es, Turín y Madrid. El hecho que el mismo arquitecto – Filippo Juvarra estuviera presente en ambas residencias reales contribuye a las similitudes, y en …
L'INFLUENZA DEL GOTICO MEDITERRANEO NELL'ARCHITETTURA DEI FLORIO
2006
A scadere del centenario della targa Florio, evento di eco internazionale, l'Assessorato al turismo ha finanziato tante iniziative, tra quella di analizzare l'influenza del linguaggio aragonese nell'architettura dei Florio. Pertanto, dopo avere individuato il linguaggio precipuo in Sicilia dell'architettura aragonese, attraverso una mappatura a rete su tutto il territorio isolano, si sono analizzate le ricadute degli elementi architettonici rilevati nelle architetture commissionate dalla famiglia Florio nell'800. Un percorso affascinante ed interminabile che disvela l'architettura siciliana del '400 e quella neoclassica di Palermo nelle committenze della potente familgia.