46 research outputs found
Planetary Nebulae distances in GAIA DR2
Context: Planetary Nebula distance scales often suffer for model dependent
solutions. Model independent trigonometric parallaxes have been rare. Space
based trigonometric parallaxes are now available for a larger sample using the
second data release of GAIA. Aims: We aim to derive a high quality approach for
selection criteria of trigonometric parallaxes for planetary nebulae and
discuss possible caveats and restrictions in the use of this data release.
Methods: A few hundred sources from previous distance scale surveys were
manually cross identified with data from the second GAIA data release (DR2) as
coordinate based matching does not work reliable. The data are compared with
the results of previous distance scales and to the results of a recent similar
study, which was using the first data release GAIA DR1. Results: While the few
available previous ground based and HST trigonometric parallaxes match
perfectly to the new data sets, older statistical distance scales, reaching
larger distances, do show small systematic differences. Restricting to those
central stars, were photometric colors of GAIA show a negligible contamination
by the surrounding nebula, the difference is negligible for radio flux based
statistical distances, while those derived from H-alpha surface brightness
still show minor differences. The DR2 study significantly improves the previous
recalibration of the statistical distance scales using DR1/TGAS.Comment: 4 pages, 4 figures, accepted for publication in Astronomy &
Astrophysics (Letter
The interacting binary V 393 Scorpii: another clue for Double Periodic Variables
We give a brief report on spectroscopic properties of V 393 Scorpii. H alfa
emission and shape and radial velocity of He I 5875 are modulated with the long
cycle. The long cycle is explained as a relaxation cycle in the circumprimary
disc, that cumulates the mass transferred from the donor until certain
instability produces disc depletion.Comment: 2 pages, 2 figures in encapsulated postscript format. To be published
in Proceedings IAU Symposium No.262, 200
Empatía como emoción emergente en el proceso de enseñanza y aprendizaje
The educational processes lead to diverse emotions that emerge from the relationality. On many occasions, these emotions are denied due to the demands of the educational system. Scarce spaces for reflection and feedback cause a senseless educational work. The possibility of giving rise to the emergence of our emotions, allows the validation of being with another. One of the emotions that allows and responds both in the task of everyday life and in educational processes is empathy. Reflect on the emotion of empathy, its dimensions from the biological, language and education allow us a closer approach to the relationship with the other, to be understood through the reconciliation of our positions, allowing us to be in the other, and above all grow collectively, dialogically and with openness of our emotionsLos procesos educativos conllevan a diversas emociones que emergen desde la relacionalidad. En muchas ocasiones, estás emociones se ven negadas debido a las exigencias propias del sistema educativo. Escasos espacios de reflexión y de retroalimentación provocan un sin sentido del quehacer educativo. La posibilidad de darlugar a la emergencia de nuestras emociones, permite la validación del estar con otro. Una de las emociones que permite y responde tanto en el quehacer de la vida cotidiana como también en los procesos educativos es la empatía. Reflexionar acerca de la emoción de la empatía, sus dimensiones desde lo biológico, el lenguaje y la educación nos permiten un mayor acercamiento a la relación con el otro, a poder comprenderse a través de la conciliación de nuestras posturas, de permitirnos ser en el otro, y por sobre todo crecer de manera colectiva, dialógica y con apertura de nuestras emociones
Diversidad y ecología de macrohongos en la Reserva Llancahue: un sitio prioritario para la conservación
Llancahue corresponde a un fragmento de bosque templado lluvioso, que se constituye en una verdadera reserva de la biodiversidad ubicada en la zona costera de la Región de Los Ríos. Con una superficie aproximada de 1.300 hectáreas, no sólo constituye la principal fuente de agua para la ciudad de Valdivia, sino que también presenta uno de los bosques más antiguos de la Provincia, por lo cual la Reserva Llancahue fue declarada recientemente como área protegida con fines de conservación y desarrollo sostenible. Debido a la escasa información existente sobre la diversidad de hongos presentes en la Reserva, se realizó muestreos estacionales durante el año 2016 e inicios del año 2017, con el fin de realizar un levantamiento de información sobre el componente hongos en este ecosistema boscoso. Los resultados obtenidos corresponden a un total de 38 especies de hongos determinadas de las cuales 23 son saprótrofas (50%), 11 ectomicorrícicas (28%) y 4 parásitas (13%), siendo otoño la época con mayor fructificación de hongos
Optical spectroscopy of DPVs and the case of LP Ara
We present preliminary results of our spectroscopic campaign of a group of
intermediate mass interacting binaries dubbed "Double Periodic Variables"
(DPVs), characterized by orbital light curves and additional long photometric
cycles recurring roughly after 33 orbital periods (Mennickent et al. 2003,
2005). They have been interpreted as interacting, semi-detached binaries
showing cycles of mass loss into the interstellar medium (Mennickent et al.
2008, Mennickent & Kolaczkowski 2009). High resolution Balmer and helium line
profiles of DPVs can be interpreted in terms of mass flows in these systems. A
system solution is given for LP Ara, based on modeling of the ASAS V-band
orbital light curve and the radial velocity of the donor star.Comment: To be published in the proceedings book of the IAUS 272, Cambridge
University Press. Editors C. Neiner, G. Wade, G. Meynet and G. Peter
2-[2-(4-Acetylphenyl)hydrazinylidene]-1,3-diphenylpropane-1,3-dione
In the title compound, C23H18N2O3, the interplanar angle between the benzoyl units is 80.51 (6)° while the dihedral angles between the hydrazinylidene and benzoyl groups are 43.43 (6) and 54.16 (6)°. In the crystal, a strong resonance-assisted intramolecular N—H⋯O hydrogen bond is observed. The molecules form an inversion dimer via a pair of weak C—H⋯O hydrogen bonds and a π–π interaction [centroid–centroid distance of 3.5719 (10) Å]. These dimers are linked via weak C—H⋯O contacts, forming chains along the b axis
2-[2-(4-Bromophenyl)hydrazinylidene]-1,3-diphenylpropane-1,3-dione
The conformation of the title molecule, C21H15BrN2O2, is stabilized by a weak intramolecular C—H⋯N hydrogen bond and a strong resonance-assisted N—H⋯O intramolecular hydrogen bond. In the crystal, the molecules are linked by weak intermolecular C—H⋯O interactions, forming zigzag chains along the b axis
A second monoclinic polymorph of 2-[2-(4-methoxyphenyl)hydrazinylidene]-1,3-diphenylpropane-1,3-dione
The title compound, C22H18N2O3 is the second monoclinic polymorph (P21/c) of the compound, the first being reported in space group P21 [Bertolasi et al. (1993 ▶). J. Chem. Soc. Perkin Trans. 2, pp. 2223–2228]. In the molecular structure of the title compound, the interplanar angle between the benzoyl units is 80.04 (5)°, while the corresponding angles between the phenylhydrazinylidene and benzoyl groups are 36.11 (5) and 55.77 (2)°. A strong resonance-assisted intramolecular N—H⋯O hydrogen bond is found. In the crystal, the entire supramolecular structure is constructed by weak intermolecular C—H⋯O interactions and an inter-ring π–π interaction [centroid–centroid distance = 3.6088 (8) Å]
Cuidado personal de niños, niñas y adolescentes en caso de separación de los padres en Chile: desde el cuidado único de la madre hasta la custodia compartida
This article presents the legislative evolution of the institution of sole custody of children in the Chilean legal system, showing the legal consecration of the institution and its legal modifications. Moreover, it goes further into the current situation of the said institution, addressing topics such as parental co-responsibility, shared custody, parents’ situations of inability and the exercise of sole custody by different people. Finally, a brief projective analysis of the issue is made in the light of international human rights law standards and the contemporary Chilean reality.El presente trabajo expone la evolución legislativa de la institución del cuidado personal de los hijos e hijas en el ordenamiento jurídico chileno, mostrando la consagración legal de la institución y sus modificaciones legales. Además, profundiza en la situación actual de la institución en comento, abordando tópicos como la corresponsabilidad parental, el cuidado personal compartido, las situaciones de inhabilidad de los padres y el ejercicio del cuidado personal por personas diferentes. Finalmente, se hace un breve análisis proyectivo de la cuestión a la luz de estándares establecidos por instrumentos internacionales de derechos humanos y la realidad chilena contemporánea
Stellar Astrophysics and Exoplanet Science with the Maunakea Spectroscopic Explorer (MSE)
The Maunakea Spectroscopic Explorer (MSE) is a planned 11.25-m aperture
facility with a 1.5 square degree field of view that will be fully dedicated to
multi-object spectroscopy. A rebirth of the 3.6m Canada-France-Hawaii Telescope
on Maunakea, MSE will use 4332 fibers operating at three different resolving
powers (R ~ 2500, 6000, 40000) across a wavelength range of 0.36-1.8mum, with
dynamical fiber positioning that allows fibers to match the exposure times of
individual objects. MSE will enable spectroscopic surveys with unprecedented
scale and sensitivity by collecting millions of spectra per year down to
limiting magnitudes of g ~ 20-24 mag, with a nominal velocity precision of ~100
m/s in high-resolution mode. This white paper describes science cases for
stellar astrophysics and exoplanet science using MSE, including the discovery
and atmospheric characterization of exoplanets and substellar objects, stellar
physics with star clusters, asteroseismology of solar-like oscillators and
opacity-driven pulsators, studies of stellar rotation, activity, and
multiplicity, as well as the chemical characterization of AGB and extremely
metal-poor stars.Comment: 31 pages, 11 figures; To appear as a chapter for the Detailed Science
Case of the Maunakea Spectroscopic Explore