A FUSE View of the Stellar Winds of Planetary Nebula Central Stars

Since the IUE satellite produced a vast collection of high-resolution UV spectra of central stars of planetary nebulae (CSPNe), there has not been any further systematic study of the stellar winds of these stars. The high spectral resolution, sensitivity and large number of archival observations in the FUSE archive allow the study of the stellar winds of CSPNe in the far UV domain where lines of species spanning a wide excitation range can be observed. We present here a preliminary analysis of the P Cygni profiles of a sample of 60 CSPNe observed by FUSE. P Cygni profiles evidencing fast stellar winds with velocities between 200 and 4,300 km/s have been found in 40 CSPNe. In many cases, this is the first time that fast stellar winds have been reported for these PNe. A detailed study of these far-UV spectra is on-going.Comment: 4 pages, 3 figures; accepted, to appear in Publications of the Astronomical Society of Australi

Las actividades físico-deportivas en el medio natural y sus efectos sobre la salud y la calidad de vida : factores psicológicos asociados

Este trabajo presenta una análisis de los factores psicológicos asociados a un tipo concreto de actividad físico-deportiva que en los últimos años ha sufrido un importante auge: Las actividades físicodeportivas desarrolladas en un entorno natural. Tomando inicialmente, como punto de partida algunos planteaminetos teóricos desarrollados al respecto en la literatura especializada (Martin y Priest, 1986), efectuamos un estudio teórico-conceptual en referencia a las implicaciones de la práctica de este tipo de actividad deportiva sobre la salud y la calidad de vida, definiendo para ello los elementos que caracterizan a este tipo de actividades: riesgo-desafio, variedad-diversidad, diversión y superación personal. Finalmente se abordan los posibles efectos psicológicamente beneficiosos que pueden derivarse de su práctica. Entre las conclusiones aportadas, consideramos que esta tipologia de práctica físico-deportiva -debido a sus propiedades de caracter motivacional-, es una alternativa con ámplias posibilidades dentro del ámbito de la actividad física y su relación con la salud.This work presents an analysis of the psychological factors associated to a specific kind of sports and physical activities which are experimenting in the last years a significant increase: sports and physical activities in a natural environment. The start point of the analysis are certain theoretical approaches to the subject present in related specialized studies (Martin and Priest, 1986). A theoreticalconceptual study of the implications of the practice of this kind of activities on health and life quality is then developed, in which the elements characterizing this type of activities are defined: risk-challenge, varietydiversity, entertainment-personal improvement. We finally analize the possible psychological benefits

CRIRES-VLT high-resolution spectro-astrometry as a tool in the search of small structures at the cores of Planetary Nebulae

The onset of the asymmetry in planetary nebulae (PNe) occurs during the short transition between the end of the asymptotic giant branch (AGB) phase and the beginning of the PN phase. Sources in this transition phase are compact and emit intensely in infrared wavelengths, making high spatial resolution observations in the infrared mandatory to investigate the shaping process of PNe. Interferometric VLTI IR observations have revealed compelling evidence of disks at the cores of PNe, but the limited sensitivity, strong observational constraints, and limited spatial coverage place severe limits on the universal use of this technique. Inspired by the successful detection of proto-planetary disks using spectro-astrometric observations, we apply here for the first time this technique to search for sub-arcsecond structures in PNe. Our exploratory study using CRIRES (CRyogenic high-resolution Infra-Red Echelle Spectrograph) commissioning data of the proto-PN IRAS 17516-2525 and the young PN SwSt 1 has revealed small-sized structures after the spectro-astrometric analysis of the two sources. In IRAS 17516-2525, the spectro-astrometric signal has a size of only 12 mas, as detected in the Brackett-gamma line, whereas the structures found in SwSt 1 have sizes of 230 mas in the [Fe III] line and 130 mas in the Brackett-gamma line. The spectroscopic observations required to perform spectro-astrometry of sources in the transition towards the PN phase are less time consuming and much more sensitive than VLTI IR observations. The results presented here open a new window in the search of the small-sized collimating agents that shape the complex morphologies of extremely axisymmetric PNe.Comment: 6 pages, 4 figure

VISIR-VLT Images of the Water Maser Emitting Planetary Nebula K 3-35

K3-35 is an extremely young bipolar planetary nebula that contains a precessing bipolar jet and a small (radius 80 AU) water maser equatorial ring. We have obtained VISIR- VLT images of K 3-35 in the PAH1 ({\lambda}=8.6 {\mu}m), [S iv] ({\lambda}=10.6 {\mu}m), and SiC ({\lambda}=11.85 {\mu}m) filters to analize the mid-IR morphology and the temperature structure of its dust emission. The images show the innermost nebular regions undetected at optical wavelegths and the precessing bipolar jets. The temperature map shows variations in the temperature in the equatorial zone and in regions associated to its jets.Comment: 2 pages, 2 figures, 283 IAU Symp. Planetary Nebulae an Eye to the Futur

The Decline and Fall of the Youngest Planetary Nebula

The Stingray Nebula, aka Hen3-1357, appeared for the first time in 1990 when bright nebular lines and radio emission that had not been observed before were unexpectedly discovered (Parthasarathy et al. 1993). In the ensuing years the nebula faded precipitously. We report changes in shape and large decreases in its nebular emission-line fluxes based on well-calibrated images obtained by the Hubble Space Telescope in 1996 and 2016. Hen3-1357 is now a "recombination nebula".Comment: 5 rages, 2 figures, 1 tabl

Physical Structure of the Planetary Nebula NGC 3242 from the Hot Bubble to the Nebular Envelope

One key feature of the interacting stellar winds model of the formation of planetary nebulae (PNe) is the presence of shock-heated stellar wind confined in the central cavities of PNe. This so-called hot bubble should be detectable in X-rays. Here we present XMM-Newton observations of NGC 3242, a multiple-shell PN whose shell morphology is consistent with the interacting stellar winds model. Diffuse X-ray emission is detected within its inner shell with a plasma temperature ~2.35\times10^6 K and an intrinsic X-ray luminosity ~2\times10^30 ergs s^(-1) at the adopted distance of 0.55 kpc. The observed X-ray temperature and luminosity are in agreement with "ad-hoc" predictions of models including heat conduction. However, the chemical abundances of the X-ray-emitting plasma seem to imply little evaporation of cold material into the hot bubble, whereas the thermal pressure of the hot gas is unlikely to drive the nebular expansion as it is lower than that of the inner shell rim. These inconsistencies are compounded by the apparent large filling factor of the hot gas within the central cavity of NGC 3242. Subject headings: planetary nebulae: individual (NGC 3242)Comment: Accepted the publication in Astronomical Journa

The triple-shell structure and collimated outflows of the planetary nebula NGC 6891

Narrow-band H$\alpha$ and [N {\sc ii}] images and high-dispersion spatially-resolved echelle spectroscopy of the planetary nebula NGC 6891 are presented. These observations show a great wealth of structures. The bright central nebula is surrounded by an attached shell and a detached outer halo. Both the inner and intermediate shells can be described as ellipsoids with similar major to minor axial ratios, but different spatial orientations. The kinematical ages of the intermediate shell and halo are 4,800 and 28,000 years, respectively. The inter-shell time lapse is in good agreement with the evolutionary inter-pulse time lapse. A highly collimated outflow is observed to protrude from the tips of the major axis of the inner nebula and impact on the outer edge of the intermediate shell. Kinematics and excitation of this outflow provide conclusive evidence that it is deflected during the interaction with the outer edge of the intermediate shell. At the same time, both the kinematics and the morphology of the intermediate shell appear to be affected by this interaction.Comment: To be published in MNRAS, 9 pages, 5 figure

Micropropagation of grape rootstocks of interest for Misiones province

Con el objeto de micropropagar portainjertos de vid de interés para la provincia de Misiones (Paulsen 1103 y Vr 04343) se cultivaron segmentos nodales y ápices meristemáticos. Para el establecimiento de segmentos nodales se evaluaron diferentes concentraciones del medio propuesto por Murashige y Skoog (MS) -¼, ½, 1- adicionando diferentes concentraciones de benciladenina (0; 1; 3 y 5 mg.L-1) y ácido naftalenacético (0 y 0,01 mg.L-1). Se evaluaron estado fisiológico y topófisis de yemas. En fase de multiplicación se evaluaron ápices, segmentos uni y binodales con o sin hoja desplegada. Para el establecimiento de ápices se evaluó el medio MS ½ suplementado con bencilaminopurina (0; 0,5; 1; 2 mg.L-1). Los mejores resultados para el establecimiento de segmentos nodales se obtuvieron con yema despierta en medio MS ¼ sin adición de reguladores. La multiplicación de los mismos puede realizarse partiendo de un explanto uni o binodal con o sin hoja. Al utilizar ápices como explanto, se debe adicionar al medio MS ½ bencilaminopurina en una concentración de 0,5 mg.L-1. En la aclimatación de las plantas, se obtuvieron valores de supervivencia de 80 a 90%.In order to develop a micropropagation system for different grape rootstock of interest for Misiones Province (Paulsen 1103 and Vr 04343), nodal segments and root tips were culturated. Different concentrations of the medium proposed by Murashige and Skoog (MS) -¼, ½ , 1- adding different concentrations of benzyladenine (0; 1; 3 and 5 mg.L-1) and naphthylacetic acid (0 and 0.01 mg.L-1) were evaluated for the establishment of nodal segments. Topofisis and physiological state of the buds were also evaluated. Shoot tips and one-node and twonode segments with or without leave were evaluated in the multiplication stage. For the establishment of shoot tips the medium MS ½ supplemented with benzylaminopurine (0; 0.5; 1; 2 mg.L-1) was evaluated. The best results for establishment phase of nodal segments with the bud were obtained with the medium MS ¼ without regulator’s addition. Multiplication phase can start from an one or two-node explant with or without leaf. When using shoot tips as explant, the medium MS ½ should be added with benzyladenine at 0.5 mg.L-1. In acclimated plants, we obtained survival values between 80 and 90%.Fil: Guerrero, Diego R.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Mroginski, Luis A.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Krivenky, Mario A.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro AzulFil: Domínguez, Martín C.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro Azu

Sub-arcsecond Morphology of Planetary Nebulae

Planetary nebulae (PNe) can be roughly categorized into several broad morphological classes. The high quality images of PNe acquired in recent years, however, have revealed a wealth of fine structures that preclude simplistic models for their formation. Here we present narrow-band, sub-arcsecond images of a sample of relatively large PNe that illustrate the complexity and variety of small-scale structures. This is especially true for bipolar PNe, for which the images reveal multi-polar ejections and, in some cases, suggest turbulent gas motions. Our images also reveal the presence or signs of jet-like outflows in several objects in which this kind of component has not been previously reported.Comment: 7 pages, 7 figures, Accepted for publication in PAS

FUSE Observations of Nebular O VI Emission from NGC 6543

NGC 6543 is one of the few planetary nebulae (PNe) whose X-ray emission has been shown to be extended and originate from hot interior gas. Using FUSE observations we have now detected nebular O VI emission from NGC 6543. Its central star, with an effective temperature of ~50,000 K, is too cool to photoionize O V, so the O VI ions must have been produced by thermal collisions at the interface between the hot interior gas and the cool nebular shell. We modeled the O VI emission incorporating thermal conduction, but find that simplistic assumptions for the AGB and fast wind mass loss rates overproduce X-ray emission and O VI emission. We have therefore adopted the pressure of the interior hot gas for the interface layer and find that expected O VI emission to be comparable to the observations.Comment: 4 pages, 4 figures, 1 table, using emulateapj.cls style. Accepted for publication in ApJ Letter