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Thermonuclear and core-collapse supernova remnants (SNRs) are the nebular leftovers of defunct stars. Their morphology and emission properties provide insights into the evolutionary history of the progenitor star. But while some SNRs are spherical, as expected from a point-like explosion expanding into a roughly uniform medium, many others exhibit complex non-spherical morphologies which are often not easily explained. In this work, we use three-dimensional magnetohydrodynamic simulations to show that rectangular and jet-like morphologies can be explained by supernovae (SNe), either type Ia or type II, expanding within anisotropic, bipolar stellar wind bubbles driven by the progenitor star. The stellar wind has an anisotropic density distribution, which channels the SN ejecta differently depending on the anisotropy characteristics. We compute synthetic thermal (X-ray) and non-thermal (synchrotron) emission maps from our numerical simulations to compare with observations. We find rectangular morphologies are generated when the stellar wind has a high mass loss rate and forms a dense, narrow disk at the equatorial region. Instead, a jet-like or ear-like morphology is obtained when the stellar wind develops a wide, dense disk. Stellar winds with low mass-loss rates do not strongly influence the SNR morphology. Finally, our synthetic synchrotron and X-ray maps for the high mass-loss rate case qualitatively agree with the observations of the SNRs G332.5-5.6 and G290.1-0.8., Comment: Accepted to MNRAS

Core-collapse supernova remnants are the gaseous nebulae of galactic interstellar media (ISM) formed after the explosive death of massive stars. Their morphology and emission properties depend both on the surrounding circumstellar structure shaped by the stellar wind-ISM interaction of the progenitor star and on the local conditions of the ambient medium. In the warm phase of the Galactic plane (n = 1/cm3, T = 8000 K), an organised magnetic field of strength 7 microG has profound consequences on the morphology of the wind bubble of massive stars at rest. In this paper we show through 2.5D magneto-hydrodynamical simulations, in the context of a Wolf-Rayet-evolving 35 Mo star, that it affects the development of its supernova remnant. When the supernova remnant reaches its middle age (15 to 20 kyr), it adopts a tubular shape that results from the interaction between the isotropic supernova ejecta and the anisotropic, magnetised, shocked stellar progenitor bubble into which the supernova blast wave expands. Our calculations for non-thermal emission, i.e. radio synchrotron and inverse Compton radiation, reveal that such supernova remnants can, due to projection effects, appear as rectangular objects in certain cases. This mechanism for shaping a supernova remnant is similar to the bipolar and elliptical planetary nebula production by wind-wind interaction in the low-mass regime of stellar evolution. If such a rectangular core-collapse supernova remnant is created, the progenitor star must not have been a runaway star. We propose that such a mechanism is at work in the shaping of the asymmetric core-collapse supernova remnant Puppis A., Accepted at MNRAS

N70 is a giant superbubble (SB) produced by the stellar cluster LH 114. The dynamic of the stellar SB can be explained with hydrodynamic simulations. However, the explanation of the observed X-ray luminosity is still a matter of debate. Observations show that this kind of superbubbles exhibits X-ray luminosities of the order of 1035 erg s−1, which cannot be explained by only considering the mechanical luminosity of the stellar components. Instead, theoretical models predict luminosities one order of magnitude lower. In this work, we attempt to answer this discrepancy by including a core-collapse supernova explosion (SN) and the photons emitted by each of the stars involved. We find that a core-collapse SN, with an initial mass of 10 M⊙, can explain the missing X-ray emission, lasting approximately 1000 yr. Also, the radiation produces an enhancement of the filamentary superbubble morphology and it increases the SB radius by $\sim 23{{\ \rm per\ cent}}$ with respect to the pure hydrodynamic case.

Full list of authors: Morgado, B. E.; Sicardy, B.; Braga-Ribas, F.; Desmars, J.; Gomes-Júnior, A. R.; Bérard, D.; Leiva, R.; Ortiz, J. L.; Vieira-Martins, R.; Benedetti-Rossi, G.; Santos-Sanz, P.; Camargo, J. I. B.; Duffard, R.; Rommel, F. L.; Assafin, M.; Boufleur, R. C.; Colas, F.; Kretlow, M.; Beisker, W.; Sfair, R.; Snodgrass, C.; Morales, N.; Fernández-Valenzuela, E.; Amaral, L. S.; Amarante, A.; Artola, R. A.; Backes, M.; Bath, K. -L.; Bouley, S.; Buie, M. W.; Cacella, P.; Colazo, C. A.; Colque, J. P.; Dauvergne, J. -L.; Dominik, M.; Emilio, M.; Erickson, C.; Evans, R.; Fabrega-Polleri, J.; Garcia-Lambas, D.; Giacchini, B. L.; Hanna, W.; Herald, D.; Hesler, G.; Hinse, T. C.; Jacques, C.; Jehin, E.; Jørgensen, U. G.; Kerr, S.; Kouprianov, V.; Levine, S. E.; Linder, T.; Maley, P. D.; Machado, D. I.; Maquet, L.; Maury, A.; Melia, R.; Meza, E.; Mondon, B.; Moura, T.; Newman, J.; Payet, T.; Pereira, C. L.; Pollock, J.; Poltronieri, R. C.; Quispe-Huaynasi, F.; Reichart, D.; de Santana, T.; Schneiter, E. M.; Sieyra, M. V.; Skottfelt, J.; Soulier, J. F.; Starck, M.; Thierry, P.; Torres, P. J.; Trabuco, L. L.; Unda-Sanzana, E.; Yamashita, T. A. R.; Winter, O. C.; Zapata, A.; Zuluaga, C. A.--This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. The Centaur (10199) Chariklo has the first ring system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow sizes and shapes to be determined with kilometre accuracy, and provide the characteristics of the occulting object and its vicinity. Aims. Using stellar occultations observed between 2017 and 2020, our aim is to constrain the physical parameters of Chariklo and its rings. We also determine the structure of the rings, and obtain precise astrometrical positions of Chariklo. Methods. We predicted and organised several observational campaigns of stellar occultations by Chariklo. Occultation light curves were measured from the datasets, from which ingress and egress times, and the ring widths and opacity values were obtained. These measurements, combined with results from previous works, allow us to obtain significant constraints on Chariklo's shape and ring structure. Results. We characterise Chariklo's ring system (C1R and C2R), and obtain radii and pole orientations that are consistent with, but more accurate than, results from previous occultations. We confirm the detection of W-shaped structures within C1R and an evident variation in radial width. The observed width ranges between 4.8 and 9.1 km with a mean value of 6.5 km. One dual observation (visible and red) does not reveal any differences in the C1R opacity profiles, indicating a ring particle size larger than a few microns. The C1R ring eccentricity is found to be smaller than 0.022 (3σ), and its width variations may indicate an eccentricity higher than ~0.005. We fit a tri-axial shape to Chariklo's detections over 11 occultations, and determine that Chariklo is consistent with an ellipsoid with semi-axes of 143.8-1.5+1.4, 135.2-2.8+1.4, and 99.1-2.7+5.4 km. Ultimately, we provided seven astrometric positions at a milliarcsecond accuracy level, based on Gaia EDR3, and use it to improve Chariklo's ephemeris. © B. E. Morgado et al. 2021., This work was carried out within the “Lucky Star” umbrella that agglomerates the efforts of the Paris, Granada and Rio teams, which is funded by the European Research Council under the European Community’s H2020 (ERC Grant Agreement No. 669416). This research made use of SORA, a python package for stellar occultations reduction and analysis, developed with the support of ERC Lucky Star and LIneA/Brazil, within the collaboration Rio-Paris-Granada teams. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Part of this research is suported by INCT do e-Universo, Brazil (CNPQ grants 465376/2014-2). Based in part on observations made at the Laboratório Nacional de Astrofísica (LNA), Itajubá-MG, Brazil. The data include observations taken by the MiNDSTEp team at the Danish 1.54 m telescope at ESO’s La Silla observatory” and “UGJ acknowledges funding from the European Union H2020-MSCA-ITN-2019 under grant no. 860470 (CHAMELEON) and from the Novo Nordisk Foundation Interdisciplinary Synergy Programme grant no. NNF19OC0057374. TRAPPIST-South is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant PDR T.0120.21. The authors acknowledge the use of Sonja Itting-Enke’s C14 telescope and the facilities at the Cuno Hoffmeister Memorial Observatory (CHMO). The following authors acknowledge the respective CNPq grants: BEM 150612/2020-6; FB-R 314772/2020-0; RV-M 304544/2017-f5, 401903/2016-8; JIBC 308150/2016-3 and 305917/2019-6; MA 427700/2018-3, 310683/2017-3, 473002/2013-2. G.B.R. acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016 and CAPES-PRINT/UNESP grant 88887.571156/2020-00, MA FAPERJ grant E-26/111.488/2013 and ARGJr FAPESP grant 2018/11239-8. J.L.O., P.S.-S., R.D., and N.M. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709), from Spanish project AYA2017-89637-R, and from FEDER. P.S.-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 “LEO-SBNAF” (MCIU/AEI/FEDER, UE). E. Jehin is a Belgian FNRS Senior Research Associate. R.S. and O.C.W. acknowledge FAPESP grant 2016/24561-0 and CNPq grant 305210/2018-1. T.C.H. acknowledges financial support from the National Research Foundation (NRF; No. 2019R1I1A1A01059609).

We homogeneously analyse $\sim 3.2\times 10^5$ photometric measurements for $\sim 1100$ transit lightcurves belonging to $17$ exoplanet hosts. The photometric data cover $16$ years 2004--2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for $13$ targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about $(-7.5\pm 2.2)$~m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly $10$ per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including $10$ ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions., Comment: 19 pages, 4 figures, 6 tables; revised manuscript submitted to MNRAS; online-only supplements are in the download archive

In the present work we have modeled the supernova remnant (SNR) G296.5+10, by means of 3D magnetohydrodynamics (MHD) simulations. This remnant belongs to the bilateral SNR group and has an additional striking feature: the rotation measure (RM) in its eastern and western parts are very different. In order to explain both the morphology observed in radio-continuum and the RM, we consider that the remnant expands into a medium shaped by the superposition of the magnetic field of the progenitor star with a constant Galactic magnetic field. We have also carried out a polarization study from our MHD results, obtaining synthetic maps of the linearly polarized intensity and the Stokes parameters. This study reveals that both the radio morphology and the reported RM for G$296.5+10$ can be explained if the quasi-parallel acceleration mechanism is taking place in the shock front of this remnant., Comment: 9 pages, 7 figures, accepted for publication in MNRAS

Three dimensional magnetohydrodynamical simulations were carried out in order to perform a new polarization study of the radio emission of the supernova remnant SN 1006. These simulations consider that the remnant expands into a turbulent interstellar medium (including both magnetic field and density perturbations). Based on the referenced-polar angle technique, a statistical study was done on observational and numerical magnetic field position-angle distributions. Our results show that a turbulent medium with an adiabatic index of 1.3 can reproduce the polarization properties of the SN 1006 remnant. This statistical study reveals itself as a useful tool for obtaining the orientation of the ambient magnetic field, previous to be swept up by the main supernova remnant shock., Comment: 8 pages, 7 figures, accepted for publication in MNRAS

Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur-that is, one of a class of small objects orbiting primarily between Jupiter and Neptune-with an equivalent radius of 124â â 9â kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites. © 2014 Macmillan Publishers Limited. Fil: Braga Ribas, F.. Observatório Nacional; Brasil Fil: Sicardy, B.. Universite Pierre et Marie Curie; Francia Fil: Ortiz, J.L.. Consejo Superior de Investigaciones Científicas; España Fil: Snodgrass, C.. Max Planck Institute for Solar System Research; Alemania Fil: Roques, F.. Universite Pierre et Marie Curie; Francia Fil: Vieira Martins, R.. Centre National de la Recherche Scientifique; Francia. Universidade Federal do Rio de Janeiro; Brasil Fil: Camargo, J.I.B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Assafin, M.. Universidade Federal do Rio de Janeiro; Brasil Fil: Duffard, R.. Consejo Superior de Investigaciones Científicas; España Fil: Jehin, E.. Université de Liège; Bélgica Fil: Pollock, J.. Appalachian State University; Estados Unidos Fil: Leiva, R.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; Chile Fil: Emilio, M.. Universidade Estadual de Ponta Grossa; Brasil Fil: MacHado, D.I.. Universidade Estadual Do Oeste Do Pará; Brasil Fil: Colazo, C.. Universidad Nacional de Córdoba; Argentina. Ministerio de Educación de la Provincia de Córdoba; Argentina Fil: Lellouch, E.. Universite Pierre et Marie Curie; Francia Fil: Skottfelt, J.. University of Copenhagen; Dinamarca. Geological Museum; Dinamarca Fil: Gillon, M.. Université de Liège; Bélgica Fil: Ligier, N.. Universite Pierre et Marie Curie; Francia Fil: Maquet, L.. Universite Pierre et Marie Curie; Francia Fil: Benedetti Rossi, G.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Gomes, A. Ramos. Universidade Federal do Rio de Janeiro; Brasil Fil: Kervella, P.. Universite Pierre et Marie Curie; Francia Fil: Monteiro, H.. Instituto de Física e Química; Brasil Fil: Sfair, R.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Moutamid, M. El. Universite Pierre et Marie Curie; Francia. Centre National de la Recherche Scientifique; Francia Fil: Tancredi, G.. Observatorio Astronómico Los Molinos; Uruguay. Universidad de la República; Uruguay Fil: Spagnotto, J.. Observatorio El Catalejo la Pampa; Argentina Fil: Maury, A.. San Pedro de Atacama Celestial Explorations; Chile Fil: Morales, N.. Consejo Superior de Investigaciones Científicas; España Fil: Gil Hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; Argentina Fil: Roland, S.. Observatorio Astronómico Los Molinos; Uruguay Fil: Ceretta, A.. Universidad de la República; Uruguay. Observatorio del IPA; Uruguay Fil: Gu, S.-H.. Chinese Academy of Sciences; República de China Fil: Wang, X.-B.. Chinese Academy of Sciences; República de China Fil: Harpsøe, K.. University of Copenhagen; Dinamarca. Geological Museum; Dinamarca Fil: Rabus, M.. Universidad Católica de Chile; Chile. Pontificia Universidad Católica de Chile; Chile. Max Planck Institute for Astronomy; Alemania Fil: Manfroid, J.. Université de Liège; Bélgica Fil: Opitom, C.. Université de Liège; Bélgica Fil: Vanzi, L.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; Chile Fil: Mehret, L.. Universidade Estadual de Ponta Grossa; Fil: Lorenzini, L.. Polo Astronômico Casimiro Montenegro Filho; Brasil Fil: Schneiter, E.M.. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Iate-conicet; Argentina Fil: Melia, R.. Universidad Nacional de Córdoba; Argentina Fil: Lecacheux, J.. Universite Pierre et Marie Curie; Francia Fil: Colas, F.. Centre National de la Recherche Scientifique; Francia Fil: Vachier, F.. Centre National de la Recherche Scientifique; Francia Fil: Widemann, T.. Universite Pierre et Marie Curie; Francia Fil: Almenares, L.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Sandness, R.G.. San Pedro de Atacama Celestial Explorations; Chile Fil: Char, F.. Universidad de Antofagasta; Chile Fil: Perez, V.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Lemos, P.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Martinez, N.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Jørgensen, U.G.. Universidad de Copenhagen; Dinamarca Fil: Dominik, M.. University of St. Andrews; Reino Unido Fil: Roig, F.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Reichart, D.E.. University of North Carolina; Estados Unidos Fil: Lacluyze, A.P.. University of North Carolina; Estados Unidos Fil: Haislip, J.B.. University of North Carolina; Estados Unidos Fil: Ivarsen, K.M.. University of North Carolina; Estados Unidos Fil: Moore, J.P.. University of North Carolina; Estados Unidos Fil: Frank, N.R.. University of North Carolina; Estados Unidos Fil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina

Context. Observational dark sinuous inflows moving sunwards, along a fan of rays were previously numerically reproduced with two simulations of 1.5D for the first time. We showed that the dark tracks can be explained as hot plasma voids generated upstream of a slow magnetoacoustic shock wave that is produced by a localized deposition of energy. Aims. We aim to confirm our “dark lane” interpretation and to identify specific 2D contributions to the description of the phenomenon. Methods. To solve the ideal and non-stationary MHD equations we used a 2D Riemann solver Eulerian code specially designed to capture supersonic flow discontinuities. Results. The numerical 2D results agree with the observational behaviour, but they show a slight shift in the characteristic parameter with respect to those found previously. Conclusions. We qualitatively confirm the behaviour found in previous papers. For a given numerical domain the period of the kinklike structure is a function of the magnetic field intensity: larger periods are associated with lower magnetic field intensities. Contrary to the 1.5D result – where the sunwards dynamic is independent of the magnetic field intensity owing to its exclusive waveguide role – in the 2D simulation the sunwards speed is higher for higher values of the magnetic field. This can be interpreted as the capability of the low coronal plasma to collimate the deposition of energy into the magnetic field direction. The moving features that consist on low-density and high-temperature plasma cavities have higher inside values of the structuring parameter β than the neighbouring media. Thus, the voids seem to be the emergence structures of a whole nonlinear interacting plasma context of shocks and waves instead of voided plasma loops that are magnetically structured.