319 research outputs found
CN and CH bands in Exoplanet Host Stars
En este trabajo medimos la intensidad de las bandas moleculares CN y CH en una muestra de estrellas con y sin exoplanetas (indices δS3839, δS4142 y δCH4300). El índice δS3839 parece ser menor en estrellas sin exoplanetas. El hecho de que la banda CN aumente con la metalicidad, puede explicar al menos en parte las diferentes distribuciones observadas en estrellas con y sin exoplanetas. Advertimos que hasta el momento las muestras son relativamente pequeñas.We measured the strength of CN and CH molecular bands in a sample of stars with and without exoplanets (indices δS3839, δS4142 and δCH4300). The index δS3839 seem to present smaller values for stars without exoplanets. No correlation is found between molecular bands and exoplanet parameters, supporting the primordial hypothesis of planet formation. The CN band strength seem to increase with C, N and Fe abundances. This could explain at least in part the dissimilar distributions of CN observed for stars with and without exoplanets. We caution that this is an initial result based in relatively small number of objects.Fil: Saffe, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Jofre, Jorge Emiliano. Universidad Nacional de Córdoba; ArgentinaFil: Petrucci, Romina. Universidad Nacional de Córdoba; Argentin
Metalicidad de estrellas con exoplanetas y discos de polvo
We present an uniform comparison among three different kind of objects: cool-Jupiter exoplanet host-stars, stars with dust disks and exoplanet host-stars with dust disks. The goal of this contribution was to determine why stellar objects originally surrounded by planetesimals evolve to different final configurations, from stars with planets to stars with debris disks.Realizamos una comparación uniforme de las metalicidades de tres grupos de objetos diferentes: estrellas con planetas del tipo Júpiter frío, estrellas con discos de polvo y estrellas que poseen tanto planetas como discos de polvo. El objetivo de esta contribución fue el de indagar sobre los motivos por los cuales objetos estelares que originalmente son circundados por planetesimales, evolucionan hacia configuraciones finales distintas, que van desde estrellas con compañeras de masa planetaria hasta estrellas rodeadas por discos de partículas sólidas.Fil: Petrucci, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio(i); ArgentinaFil: Saffe, Carlos. Consejo Nacional de Investigaciones Cientiâficas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Fisicas y Naturales; ArgentinaFil: Jofré, E.. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Automated code for the selection of targets to be observed with the SAINT-EX telescope
In this contribution, we present the main characteristics and describe the functioning of the code developed in python language to automatically build the list of objects that are nightly observed in queue mode with the 1-m SAINT-EX telescope.Fil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gómez Maqueo Chew, Yilen. Instituto de Astronomia; México. Universidad Nacional Autónoma de México; Méxic
Automated code for the selection of targets to be observed with the SAINT-EX telescope
In this contribution, we present the main characteristics and describe the functioning of the code developed in python language to automatically build the list of objects that are nightly observed in queue mode with the 1-m SAINT-EX telescope.Fil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gómez Maqueo Chew, Yilen. Instituto de Astronomia; México. Universidad Nacional Autónoma de México; Méxic
Estudio de variaciones en los tiempos de mínimo en estrellas con planetas transitantes del Hemisferio Sur
Tesis (Doctor en Astronomía)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía y Física, 2015.En este trabajo presentamos los resultados del monitoreo y análisis homogéneo de tránsitos de planetas que orbitan alrededor de estrellas del Hemisferio Sur. El propósito principal de este seguimiento fotométrico es el de buscar variaciones en los tiempos de mínimo (TTVs) que pudieran atribuirse a la presencia de otros cuerpos de masa planetaria no detectados, ligados gravitacionalmente al sistema.
Para ello realizamos observaciones con los telescopios argentinos Horacio Ghielmetti (THG) de 40 cm localizado en el Complejo Astronómico El Leoncito (CASLEO) y el telescopio de 1.54 m ubicado en la Estación Astrofísica de Bosque Alegre (EABA).
Dado que se requieren muchos datos para llevar a cabo análisis de TTVs confiables, sólo estudiamos las 3 estrellas de nuestra muestra inicial que presentaron más de 10 observaciones entre propias y extraídas de la literatura. Como subproducto del análisis de variaciones en los tiempos de mínimo, para cada uno de nuestros objetos computamos nuevas efemérides y re-determinamos los parámetros físicos de la estrella y el planeta. Considerando que los puntos analizados comprenden como mínimo 3 años de observaciones, además de estudiar las variaciones a largo plazo de los tiempos de mínimo, evaluamos las variaciones en la inclinación de la órbita (i) y la profundidad del tránsito (k) que también pudieran atribuirse a la presencia de otro cuerpo de masa planetaria en el sistema
The lizard celestial compass detects linearly polarized light in the blue
SummaryThe present study first examined whether ruin lizards Podarcis sicula are able to orientate using plane polarized light produced by a LCD screen. Ruin lizards were trained and tested indoors, inside an hexagonal Morris water maze, positioned under the LCD screen producing white polarized light with a single E-vector, which provided an axial cue. White polarized light did not include wavelengths in the UV. Lizards orientated correctly either when tested with E-vector parallel to the training axis or after 90° rotation of the E-vector direction, and thus validating the apparatus. Further experiments examined whether in ruin lizards there is a preferential region of the light spectrum to perceive the E-vector direction of polarized light. For this purpose, lizards reaching learning criteria under white polarized light were subdivided into 4 experimental groups. Each group was respectively tested for orientation under a different spectrum of plane polarized light (named red, green, cyan and blue) with equalized photon flux density. Lizards tested under blue polarized light orientated correctly, whereas lizards tested under red polarized light were completely disoriented. Green polarized light was barely discernible by lizards, and thus insufficient for a correct functioning of their compass. When exposed to cyan polarized light, lizard orientation performances were optimal, indistinguishable from lizards detecting blue polarized light. Overall, the present results demonstrate that perception of linear polarization in the blue is necessary - and sufficient - for a proper functioning of the sky polarization compass of ruin lizards. This may be adaptively important, since detection of polarized light in the blue improves functioning of the polarization compass under cloudy skies, i.e. when the alternative celestial compass based on detection of the sun disk is rendered useless because the sun is obscured by clouds
Psychometric properties of the Jefferson Scale of Empathy-Health Professional Student's version: an Italian validation study with nursing students.
This methodological study was conducted to test the psychometric properties of the Jefferson Scale of Empathy - Health Professional Student's version (JSE-HPS). It used a convenience sample of 797 Italian nursing students and also aimed to describe their empathic engagement. Data were subjected to exploratory and confirmatory factor analysis, test-retest, correlation analysis, t-test, and analysis of variance method. Principal component factor extraction with Oblimin rotation on the first half of the sample was conducted. The analysis suggested a three-factor solution for 14 items: compassionate care/emotional engagement, perspective-taking, and standing in the patient's shoes. Confirmatory factor analysis on the second half of the sample showed good fit indexes for the 14-item solution, indicated by the exploratory factor analysis, and the 20 item solution of the scale, with the exception of one item. Test-retest correlation was 0.50 (P < -0.001) for the overall scale. Results from group comparisons and correlations are also provided and discussed. The Italian version of the JSE-HPS is a psychometrically sound tool. The translated 20-item solution is also suitable to carry out cross-cultural comparisons
Impact of dealcoholization by osmotic distillation on metabolic profile, phenolic content, and antioxidant capacity of low alcoholic craft beers with different malt compositions
Beer antioxidants originate mainly from malts, classified as colored, caramel, and roasted, according to the malting process. This study aimed to characterize, in terms of phenolic antioxidants, three types of Pale Ale craft beers brewed using increasing percentage of dark malt (0, 5, and 15% Caraamber malt, called PA100, PA95, PA85, respectively) and to evaluate the impact of dealcoholization by osmotic distillation (OD) on the same antioxidants. All the alcoholic (PA, 6.2-6.8 vol %) and low alcoholic (LA-PA, 1 vol %) beers were analyzed by HPLC-ESI-MS/MS, total phenolic content (TPC), and antioxidant activity (AA): similar phenolic profiles were evidenced and 43 compounds identified or tentatively identified. Some differences were found among PA100, PA95, and PA85: PA85 was richer in free phenolic compounds (10.55 mg/L) and had a higher TPC (463.7 GAE mg/L) and AA (852.1 TE mg/L). LA-PA beers showed the same phenolic profile and similar TPC and AA compared to PA beers; however, there were some differences regarding LA-PA85 (5.91 mg/L). Dealcoholization by OD seemed to weakly affect the phenolic fraction. ESI-MS/MS infusion experiments evidenced oligosaccharides, small organic acids, and amino acids, whose presence was confirmed and quantitated by NMR: besides ethanol and other alcohols, weak to strong loss of low-molecular-weight metabolites was evidenced in LA-PA beers
High-contrast imaging of HD 29992 and HD 196385 with the Gemini Planet Imager
Based on high contrast images obtained with the Gemini Planet Imager (GPI), we report the discovery of two point-like sources at angular separations of ∼ 0.1800 and ∼ 0.8000 from the stars HD 29992 and HD 196385. A combined analysis of the new GPI observations and images from the literature indicates that the source close to HD 29992 could be a companion to the star. Concerning HD 196385, the small number of contaminants (∼ 0.5) suggests that the detected source may be gravitationally bound to the star. For both systems, we discarded the presence of other potential companions with > 75 MJup at ∼ 0.3−1.3 00. From stellar model atmospheres and low-resolution GPI spectra, we derive masses of ∼ 0.2 - 0.3 M for these sources. Using a Markov-chain Monte Carlo approach, we performed a joint fit of the new astrometry measurements and published radial velocity data to characterize the possible orbits. For HD 196385B, the median dynamic mass is in agreement with that derived from model atmospheres, whilst for HD 29992B, the orbital fit favors masses close to the brown dwarf regime(∼ 0.08 M). HD 29992 and HD 196385 might be two new binary systems with M-type stellar companions. However, new high angular resolution images would help to definitively confirm whether the detected sources are gravitationally bound to their respective stars, and permittighter constraints on the orbital parameters of both systems.Fil: García, Luciano Héctor. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Jofre, Jorge Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; ArgentinaFil: Gomez, Mercedes Nieves. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentin
Transit timing variation analysis in southern stars: the case of WASP-28
We present four new transit observations of the exoplanet WASP-28b observed between 2011 August and 2013 October. Employing another 11 transits available in the literature we compute new ephemeris and redetermine the physical parameters of the star and the exoplanet. Considering 3 yr of observations, we find no periodic transit timing variations (TTVs) or long-term variations of the inclination of the orbit, i, or the depth of the transit, k, that could be attributable to the presence of another planetary-mass body in the system. We also study the relations between i and k with different factors that characterize the light curves. The fits suggest a possible weak correlation between k with the red noise factor, β, and the photometric noise rate, PNR, and a weak anticorrelation between i and PNR, although more points are needed to confirm these trends. Finally, the kinematic study suggests that WASP-28 is a thin-disc star.Fil: Petrucci, Romina Paola. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Jofre, Jorge Emiliano. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Melita, Mario Daniel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Gomez, Mercedes Nieves. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mauas, Pablo Jacobo David. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin
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