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

Possible chromospheric activity cycles in AD Leo

AD Leo (GJ 388) is an active dM3 flare star extensively observed both in the quiescent and flaring states. Since this active star is near the fully-convective boundary, to study in detail its long-term chromospheric activity could be an appreciable contribution for the dynamo theory. Here, we analyze with the Lomb-Scargle periodogram the Ca II K line-core fluxes derived from CASLEO spectra obtained between 2001 and 2013 and the V magnitude from the ASAS database between 2004 and 2010. From both totally independent time-series, we obtain a possible activity cycle of period $\sim7$ years and a less-significant shorter one of $\sim2$ years. A tentative interpretation is that a dynamo operating near the surface could be generating the longer cycle, while a second dynamo operating in the deep convection zone could be responsible for the shorter one. Based on the long duration of our observing program at CASLEO and the fact that we observe simultaneously different spectral features, we also analyze the relation between simultaneous measurements of the Na I index ($R^{\prime}_D$), H$\alpha$ and Ca II K fluxes at different activity levels of AD Leo, including flares.Comment: 21 pages, 3 figures.Accepted for publication in ApJ

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

Strengths and Weaknesses of Cancer Pain Management in Italy: Findings from a Nationwide SIAARTI Survey

Objectives: Despite guidelines, a large percentage of cancer patients continue to suffer from ineffectively treated pain. The authors undertook this survey to assess the strengths and weaknesses of cancer pain management in Italy. Design: This was a prospectively administered survey. Participants: The participants were anesthesiologists of the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI). Intervention: A 58-item questionnaire covered the demographics and features of cancer pain management in the Italian context. Results: The authors received responses from 611 pain therapists of 279 centers. Only 22% of physicians are exclusively pain therapists. Seventy-five percent are specialists in anesthesiology, intensive care, and pain medicine. Most pain centers are hospital or university facilities (78%). The strengths of cancer pain management in Italy are the careful opioid prescriptions, the use of strategies for the treatment of neuropathic pain, patient/healthcare provider partnerships, and breakthrough cancer pain management. Weaknesses to be addressed include poor adherence to guidelines, inadequate attention toward the patient's quality of life, insufficient use of minimally invasive techniques, lack of teamwork approaches, inappropriate timing of pain specialist engagement, and poor telemedicine use. Conclusions: Despite several strengths, further efforts are needed to improve the care of patients suffering from cancer pain in Italy

Exploring the photometric variability of ultra-cool dwarfs with TESS

We present a photometric characterization of 208 ultra-cool dwarfs (UCDs) with spectral types between M4 and L4, from 20-second and 2-minute cadence TESS light curves. We determine rotation periods for 87 objects (42 percent) and identify 778 flare events in 103 UCDs (49.5 percent). For 777 flaring events (corresponding to 102 objects), we derive bolometric energies between 2.1e30 and 1.1e34 erg , with 56 superflare events. No transiting planets or eclipsing binaries were identified. We find that the fraction of UCDs with rotation and flaring activity is, at least, 20 percent higher in M4-M6 spectral types than in later UCDs (M7-L4). For spectral types between M4 and L0, we measure the slope of the flare bolometric energy-duration correlation to be gamma = 0.497 +/- 0.058, which agrees with that found in previous studies for solar-type and M dwarfs. Moreover, we determine the slope of the flare frequency distribution to be alpha = -1.75 +/- 0.04 for M4-M5 dwarfs, alpha = -1.69 +/- 0.04 and alpha = -1.72 +/- 0.1 for M6-M7 and M8-L0 dwarfs, respectively, which are consistent with previous works that exclusively analysed UCDs. These results support the idea that independently of the physical mechanisms that produce magnetic activity, the characteristics of the rotational modulation and flares are similar for both fully-convective UCDs and partially-convective solar-type and early-M stars. Based on the measured UCD flare distributions, we find that UV radiation emitted from flares does not have the potential to start prebiotic chemistry.Comment: Accepted for publication in MNRAS, 16 pages, 12 figure

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

Espectroscopía Gemini-GRACES de estrellas evolucionadas con enanas marrones

A partir de espectros de alta resolución Gemini-GRACES, aquí se presentan parámetros fundamentales refinados y abundancias químicas detalladas de dos gigantes rojas que albergan enanas marrones, HD 54719 y HD 180314. Las abundancias químicas de ambas estrellas son consistentes con las de aquellas evolucionadas cercanas. HD 180314 presenta una abundancia relativamente alta de litio (A(Li)NLT E = 1.28 dex), que probablemente es remanente de su fase de secuencia principal. El análisis de las metalicidades de ambas estrellas indicaría, como tendencia inicial, que las gigantes con enanas marrones son pobres en metales.Based on high-resolution spectra from Gemini-GRACES, here we present refined fundamental parameters and detailed chemical abundances of two red giants hosting brown dwarfs, HD 54719 and HD 180314. The abundances of both stars are consistent with those of nearby evolved thin disk stars. HD 180314 presents a relatively high abundance of lithium (A(Li)NLT E = 1.28 dex), which is likely a remnant from the main-sequence phase. The metallicities of both stars show, as an initial trend, that giants with brown dwarfs are metal-poor.Fil: Zuloaga, Camila. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Jofré, Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Martioli, Eder. Laboratorio Nacional de Astrofisica; Brasi

Espectroscopía Gemini-GRACES de estrellas evolucionadas con enanas marrones

A partir de espectros de alta resolución Gemini-GRACES, aquí se presentan parámetros fundamentales refinados y abundancias químicas detalladas de dos gigantes rojas que albergan enanas marrones, HD 54719 y HD 180314. Las abundancias químicas de ambas estrellas son consistentes con las de aquellas evolucionadas cercanas. HD 180314 presenta una abundancia relativamente alta de litio (A(Li)NLT E = 1.28 dex), que probablemente es remanente de su fase de secuencia principal. El análisis de las metalicidades de ambas estrellas indicaría, como tendencia inicial, que las gigantes con enanas marrones son pobres en metales.Based on high-resolution spectra from Gemini-GRACES, here we present refined fundamental parameters and detailed chemical abundances of two red giants hosting brown dwarfs, HD 54719 and HD 180314. The abundances of both stars are consistent with those of nearby evolved thin disk stars. HD 180314 presents a relatively high abundance of lithium (A(Li)NLT E = 1.28 dex), which is likely a remnant from the main-sequence phase. The metallicities of both stars show, as an initial trend, that giants with brown dwarfs are metal-poor.Fil: Zuloaga, Camila. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Jofré, Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Martioli, Eder. Laboratorio Nacional de Astrofisica; Brasi