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We present the surface magnetic field conditions of the brightest pulsating RV Tauri star, R Sct. Our investigation is based on the longest spectropolarimetric survey ever performed on this variable star. The analysis of high resolution spectra and circular polarization data give sharp information on the dynamics of the atmosphere and the surface magnetism, respectively. Our analysis shows that surface magnetic field can be detected at different phases along a pulsating cycle, and that it may be related to the presence of a radiative shock wave periodically emerging out of the photosphere and propagating throughout the stellar atmosphere., 16 pages, 14 figures

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Full list of authors: De Marco, Orsola; Akashi, Muhammad; Akras, Stavros; Alcolea, Javier; Aleman, Isabel; Amram, Philippe; Balick, Bruce; De Beck, Elvire; Blackman, Eric G.; Boffin, Henri M. J.; Boumis, Panos; Bublitz, Jesse; Bucciarelli, Beatrice; Bujarrabal, Valentin; Cami, Jan; Chornay, Nicholas; Chu, You-Hua; Corradi, Romano L. M.; Frank, Adam; García-Hernández, D. A.; García-Rojas, Jorge; García-Segura, Guillermo; Gómez-Llanos, Veronica; Gonçalves, Denise R.; Guerrero, Martín A.; Jones, David; Karakas, Amanda I.; Kastner, Joel H.; Kwok, Sun; Lykou, Foteini; Manchado, Arturo; Matsuura, Mikako; McDonald, Iain; Miszalski, Brent; Mohamed, Shazrene S.; Monreal-Ibero, Ana; Monteiro, Hektor; Montez, Rodolfo; Baez, Paula Moraga; Morisset, Christophe; Nordhaus, Jason; Mendes de Oliveira, Claudia; Osborn, Zara; Otsuka, Masaaki; Parker, Quentin A.; Peeters, Els; Quint, Bruno C.; Quintana-Lacaci, Guillermo; Redman, Matt; Ruiter, Ashley J.; Sabin, Laurence; Sahai, Raghvendra; Contreras, Carmen Sánchez; Santander-García, Miguel; Seitenzahl, Ivo; Soker, Noam; Speck, Angela K.; Stanghellini, Letizia; Steffen, Wolfgang; Toalá, Jesús A.; Ueta, Toshiya; Van de Steene, Griet; Van Winckel, Hans; Ventura, Paolo; Villaver, Eva; Vlemmings, Wouter; Walsh, Jeremy R.; Wesson, Roger; Zijlstra, Albert A., Planetary nebulae—the ejected envelopes of red giant stars—provide us with a history of the last, mass-losing phases of 90% of stars initially more massive than the Sun. Here we analyse images of the planetary nebula NGC 3132 from the James Webb Space Telescope (JWST) Early Release Observations. A structured, extended hydrogen halo surrounding an ionized central bubble is imprinted with spiral structures, probably shaped by a low-mass companion orbiting the central star at about 40–60 au. The images also reveal a mid-infrared excess at the central star, interpreted as a dusty disk, which is indicative of an interaction with another closer companion. Including the previously known A-type visual companion, the progenitor of the NGC 3132 planetary nebula must have been at least a stellar quartet. The JWST images allow us to generate a model of the illumination, ionization and hydrodynamics of the molecular halo, demonstrating the power of JWST to investigate complex stellar outflows. Furthermore, new measurements of the A-type visual companion allow us to derive the value for the mass of the progenitor of a central star with excellent precision: 2.86 ± 0.06 M⊙. These results serve as pathfinders for future JWST observations of planetary nebulae, providing unique insight into fundamental astrophysical processes including colliding winds and binary star interactions, with implications for supernovae and gravitational-wave systems. © 2022, The Author(s), under exclusive licence to Springer Nature Limited., We acknowledge the International Astronomical Union that oversees the work of Commission H3 on Planetary Nebulae. It is through the coordinating activity of this committee that this paper came together. S.A. acknowledges support under the grant 5077 financed by IAASARS/NOA. J.A. and V.B. acknowledge support from the EVENTs/Nebulae-Web research programme, Spanish AEI grant PID2019-105203GB-C21. I.A. acknowledges the support of CAPES, Brazil (Finance Code 001). E.D.B. acknowledges financial support from the Swedish National Space Agency. E.G.B. acknowledges NSF grants AST-1813298 and PHY-2020249. J.C. and E.P. acknowledge support from an NSERC Discovery Grant. G.G.-S. thanks M. L. Norman and the Laboratory for Computational Astrophysics for the use of ZEUS-3D. D.A.G.-H. and A.M. acknowledge support from the ACIISI, Gobierno de Canarias and the European Regional Development Fund (ERDF) under grant with reference PROID2020010051 as well as from the State Research Agency (AEI) of the Spanish Ministry of Science and Innovation (MICINN) under grant PID2020-115758GB-I00. J.G.-R. acknowledges support from Spanish AEI under Severo Ochoa Centres of Excellence Programme 2020-2023 (CEX2019-000920-S). J.G.-R. and V.G.-L. acknowledge support from ACIISI and ERDF under grant ProID2021010074. D.R.G. acknowledges the CNPq grant 313016/2020-8. M.A.G. acknowledges support of grant PGC2018-102184-B-I00 of the Ministerio de Educación, Innovación y Universidades cofunded with FEDER funds and 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). D.J. acknowledges support from the Erasmus+ programme of the European Union under grant number 2020-1-CZ01-KA203-078200. A.I.K. and Z.O. were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. This research is/was supported by an Australian Government Research Training Program (RTP) Scholarship. M.M. and R.W. acknowledge support from STFC Consolidated grant (2422911). C.M. acknowledges support from UNAM/DGAPA/PAPIIT under grant IN101220. S.S.M. acknowledges funding from UMiami, the South African National Research Foundation and the University of Cape Town VC2030 Future Leaders Award. J.N. acknowledges support from NSF grant AST-2009713. C.M.d.O. acknowledges funding from FAPESP through projects 2017/50277-0, 2019/11910-4 e 2019/26492-3 and CNPq, process number 309209/2019-6. J.H.K. and P.M.B. acknowledge support from NSF grant AST-2206033 and a NRAO Student Observing Support grant to Rochester Institute of Technology. M.O. was supported by JSPS Grants-in-Aid for Scientific Research(C) (JP19K03914 and 22K03675). Q.A.P. acknowledges support from the HKSAR Research grants council. Vera C. Rubin Observatory is a Federal project jointly funded by the National Science Foundation (NSF) and the Department of Energy (DOE) Office of Science, with early construction funding received from private donations through the LSST Corporation. The NSF-funded LSST (now Rubin Observatory) Project Office for construction was established as an operating centre under the management of the Association of Universities for Research in Astronomy (AURA). The DOE-funded effort to build the Rubin Observatory LSST Camera (LSSTCam) is managed by SLAC National Accelerator Laboratory (SLAC). A.J.R. was supported by the Australian Research Council through award number FT170100243. L.S. acknowledges support from PAPIIT UNAM grant IN110122. C.S.C.’s work is part of I+D+i project PID2019-105203GB-C22 funded by the Spanish MCIN/AEI/10.13039/501100011033. M.S.-G. acknowledges support by the Spanish Ministry of Science and Innovation (MICINN) through projects AxIN (grant AYA2016-78994-P) and EVENTs/Nebulae-Web (grant PID2019-105203GB-C21). R.S.’s contribution to the research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. J.A.T. thanks the Marcos Moshisnky Fundation (Mexico) and UNAM PAPIIT project IA101622. E.V. acknowledges support from the ‘On the rocks II project’ funded by the Spanish Ministerio de Ciencia, Innovación y Universidades under grant PGC2018-101950-B-I00. A.A.Z. acknowledges support from STFC under grant ST/T000414/1. This research made use of Photutils, an Astropy package for detection and photometry of astronomical sources83, of the Spanish Virtual Observatory (https://svo.cab.inta-csic.es) project funded by MCIN/AEI/10.13039/501100011033/ through grant PID2020-112949GB-I00 and of the computing facilities available at the Laboratory of Computational Astrophysics of the Universidade Federal de Itajubá (LAC-UNIFEI, which is maintained with grants from CAPES, CNPq and FAPEMIG).

We report confirmation of a large, evolved, bipolar planetary nebula and its blue, white dwarf central star as a member of the ~500 Myr old Galactic open star cluster M37 (NGC 2099). This is only the third known example of a planetary nebula in a Galactic open cluster and was found via our on-going program of identifying and studying planetary nebulae - open cluster associations. High confidence in the association comes from the consistent radial velocities and proper motions for the confirmed central star and cluster stars from Gaia, reddening agreement and location of the planetary nebula well within the tidal cluster boundary. Interestingly, all three Galactic examples have bipolar morphology and likely Type I chemistry, both characteristics of higher mass progenitors. In this case the progenitor star mass is in the mid-range of ~2.8 Msun. It provides a valuable, additional point on the key stellar initial-to-final mass relation independent of cluster white dwarf estimates and also falls in a gap in the poorly sampled mass region. This planetary nebula also appears to have the largest kinematical age ever determined and implies increased visibility lifetimes when they are located in clusters., 11 pages, 5 figures, 1 table

In a continuing effort to investigate the role of magnetic fields in evolved low and intermediate mass stars (principally regarding the shaping of their envelopes), we present new ALMA high resolution polarization data obtained for the nebula OH 231.8+4.2. We found that the polarized emission likely arises from aligned grains in the presence of magnetic fields rather than radiative alignment and self scattering. The ALMA data show well organized electric field orientations in most of the nebula and the inferred magnetic field vectors (rotated by 90 degrees) trace an hourglass morphology centred on the central system of the nebula. One region in the southern part of OH 231.8+4.2 shows a less organized distribution probably due to the shocked environment. These findings, in conjunction with earlier investigations (maser studies and dust emission analysis at other scales and wavelengths) suggest an overall magnetic hourglass located inside a toroidal field. We propose the idea that the magnetic field structure is closely related to the architecture of a magnetic tower and that the outflows were therefore magnetically launched. While the current dynamical effect of the fields might be weak in the equatorial plane principally due to the evolution of the envelope, it would still be affecting the outflows. In that regard, the measurement of the magnetic field at the stellar surface, which is still missing, combined with a full MHD treatment are required to better understand and constrain the events occurring in OH 231.8+4.2., 9 pages, 7 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We present the analysis of archival XMM-Newton European Photon Imaging Camera (EPIC) X-ray observations of the symbiotic star R Aquarii. We used the Extended Source Analysis Software package to disclose diffuse soft X-ray emission extending up to 2farcm2 (≈0.27 pc) from this binary system. The depth of these XMM-Newton EPIC observations reveals in unprecedented detail the spatial distribution of this diffuse emission, with a bipolar morphology spatially correlated with the optical nebula. The extended X-ray emission shares the same dominant soft X-ray-emitting temperature as the clumps in the jet-like feature resolved by Chandra in the vicinity of the binary system. The harder component in the jet might suggest that the gas cools down; however, the possible presence of nonthermal emission produced by the presence of a magnetic field collimating the mass ejection cannot be discarded. We propose that the ongoing precessing jet creates bipolar cavities filled with X-ray-emitting hot gas that feeds the more extended X-ray bubble as they get disrupted. These EPIC observations demonstrate that the jet feedback mechanism produced by an accreting disk around an evolved, low-mass star can blow hot bubbles, similar to those produced by jets arising from the nuclei of active galaxies. © 2022. The Author(s). Published by the American Astronomical Society., J.A.T. acknowledges support by the Fundación Marcos Moshinsky (Mexico) and UNAM PAPIIT project IA101622 (Mexico). L.S. acknowledges support by UNAM PAPIIT project IN110122 (Mexico). M.A.G. acknowledges the support of grant PGC 2018-102184-B-I00 of the Ministerio de Educación, Innovación y Universidades cofunded with FEDER funds. G.R.-L. acknowledges support from CONACyT grant 263373. Y.H.C. acknowledges the grant MOST 110-2112-M-001-020 from the Ministry of Science and Technology (Taiwan). Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. This research has made use of data obtained from the Chandra Data Archive and software provided by the Chandra X-ray Center (CXC) in the application package CIAO. This work has made extensive use of NASA's Astrophysics Data System., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

We present the first instalment of a deep imaging catalogue containing 58 True, Likely, and Possible extended PNe detected with the Isaac Newton Telescope Photometric H α Survey (IPHAS). The three narrow-band filters in the emission lines of H α, [N ii] λ6584 Å, and [O iii] λ5007 Å used for this purpose allowed us to improve our description of the morphology and dimensions of the nebulae. In some cases even the nature of the source has been reassessed. We were then able to unveil new macro- and micro-structures, which will without a doubt contribute to a more accurate analysis of these PNe. It has been also possible to perform a primary classification of the targets based on their ionization level. A Deep Learning classification tool has also been tested. We expect that all the PNe from the IPHAS catalogue of new extended planetary nebulae will ultimately be part of this deep H α, [N ii], and [O iii] imaging catalogue. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society., LS acknowledges support from PAPIIT grant IN-101819 (Mexico). MAG acknowledges support from grant AYA PGC2018-102184-B-I00 co-funded with FEDER funds. GR-L acknowledges support from CONACyT (grant 263373) and PRODEP (Mexico). JAT acknowledges funding by Dirección General de Asuntos del Personal Academico of the Universidad Nacional Autónoma de México (DGAPA, UNAM) project IA100720 and the Marcos Moshinsky Fundation (Mexico). AAZ acknowledges funding from STFC under grant number ST/T000414/1 and Newton grant ST/R006768/1, and from a Hung Hing Ying visiting professorship at the University of Hong Kong. DNFAI acknowledges funding under ‘Deep Learning for Classification of Astronomical Archives’ from the Newton-Ungku Omar Fund: F08/STFC/1792/2018., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

We present a multiwavelength characterization of the planetary nebula (PN) NGC 6905 and its [Wolf–Rayet]-type ([WR]) central star (CSPN) HD 193949. Our Nordic Optical Telescope Alhambra Faint Object Spectrograph and Camera (ALFOSC) spectra and images unveil in unprecedented detail the high-ionization structure of NGC 6905. The high-quality spectra of HD 193949 allowed us to detect more than 20 WR features including the characteristic O-bump, blue bump, and red bump, which suggests a spectral type no later than a [WO2]-subtype. Moreover we detect the Ne VII and Ne VIII broad emission lines, rendering HD 193949 yet another CSPN with Teff ≲ 150 kK exhibiting such stellar emission lines. We studied the physical properties (Te and ne) and chemical abundances of different regions within NGC 6905 including its low-ionization clumps; abundances are found to be homogeneous. We used the PoWR stellar atmosphere code to model the spectrum of HD 193949, which is afterwards used in a photoionization model performed with CLOUDY that reproduces the nebular and dust properties for a total mass in the 0.31–0.47 M⊙ range and a mass of C-rich dust of ∼2 × 10−3 M⊙. Adopting a current stellar mass of 0.6 M⊙, our model suggests an initial mass ∼1 M⊙ for HD 193949, consistent with the observations. © 2021 The Author(s)., VMAGG acknowledges support from the Programa de Becas posdoctorales of the Dirección General de Asuntos del Personal Académico of the Universidad Nacional Autónoma de México (DGAPA, UNAM, Mexico). VMAGG and JAT acknowledge funding by DGAPA UNAM PAPIIT project IA100720. JAT also acknowledges support from the Marcos Moshinsky Fundation (Mexico). GR acknowledge support from Consejo Nacional de Ciencia y Tecnología (CONACYT) for student scholarship. MAG acknowledges support of the Spanish Ministerio de Ciencia, Innovación y Universidades grant PGC2018-102184-B-I00, cofunded by FEDER funds. LS acknowledges funding by DGAPA UNAM PAPIIT project IN-101819. GR-L acknowledges support from CONACYT grant 263373 and PRODEP (Mexico). This work is based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos in La Palma, Spain, of the Instituto de Astrofisica de Canarias. This work uses public data from the IR telescope Spitzer Space Telescope through the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory at the California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA). WISE is a joint project of the University of California (Los Angeles, USA) and the JPL/Caltech. The Infrared Astronomical Satellite (IRAS) was a joint project of the US, UK, and the Netherlands. This research is based on observations with AKARI, a JAXA project with the participation of ESA. This work has make extensive use of the NASA’s Astrophysics Data System., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

We present X-ray through submillimeter observations of the classical RV Tauri (RVb-type) variable U Mon, a post-AGB binary with a circumbinary disk (CBD). Our SMA observations indicate a CBD diameter of $\lesssim$550 au. Our XMM-Newton observations make U Mon the first RV Tauri variable detected in X-rays. The X-ray emission is characteristic of a hot plasma ($\sim$10 MK), with L$_{X}=5\times10^{30}{\rm erg}~{\rm s}^{-1}$, and we consider its possible origin from U Mon, its companion, and/or binary system interactions. Combining DASCH and AAVSO data, we extend the time-series photometric baseline back to the late 1880s and find evidence that U Mon has secular changes that appear to recur on a timescale of $\sim$60 yr, possibly caused by a feature in the CBD. From literature radial velocities we find that the binary companion is a $\sim$2 M$_{\odot}$ A-type main-sequence star. The orientation of the binary's orbit lies along our line of sight ($\omega = 95^\circ$), such that apastron corresponds to photometric RVb minima, consistent with the post-AGB star becoming obscured by the near side of the CBD. In addition, we find the size of the inner-CBD hole ($\sim$4.5-9 au) to be comparable to the binary separation, implying that one or both stars may interact with the CBD at apastron. The obscuration of the post-AGB star implicates the companion as the likely source of the enhanced H$\alpha$ observed at RVb minima and of the X-ray emission that may arise from accreted material., Comment: 19 pages, 9 figures, 4 tables, in aastex62 format, published in ApJ, NASA news feature available upon request. Light curve in Figure 2 available as "Data behind the Figure"

Greimel, R., et al., The INT Galactic Plane Survey (IGAPS) is the merger of the optical photometric surveys IPHAS and UVEX based on data from the Isaac Newton Telescope (INT) obtained between 2003 and 2018. It captures the entire northern Galactic plane within the Galactic coordinate range |b|< 5° and 30° < ℓ < 215°. From the beginning, the incorporation of narrow-band Hα imaging has been a unique and distinctive feature of this effort. Alongside a focused discussion of the nature and application of the Hα data, we present the IGAPS world-accessible database of images for all five survey filters, i, r, g, URGO, and narrow-band Hα, observed on a pixel scale of 0.33 arcsec and at an effective (median) angular resolution of 1.1-1.3 arcsec. The background, noise, and sensitivity characteristics of the narrow-band Hα filter images are outlined. Typical noise levels in this band correspond to a surface brightness at full ∼1 arcsec resolution of around 2 × 10-16 erg cm-2 s-1 arcsec-2. Illustrative applications of the Hα data to planetary nebulae and Herbig-Haro objects are outlined and, as part of a discussion of the mosaicking technique, we present a very large background-subtracted narrow-band mosaic of the supernova remnant Simeis 147. Finally, we lay out a method that exploits the database via an automated selection of bright ionised diffuse interstellar emission targets for the coming generation of wide-field massive-multiplex spectrographs. Two examples of the diffuse Hα map output from this selection process are presented and compared with previously published data., RG benefitted from support via STFC grant ST/M001334/1 as a visitor to UCL. JED and MM acknowledge the support of research grants funded by the Science, Technology and Facilities Council of the UK (STFC, grants ST/M001008/1 and ST/J001333/1). MM was partially supported by the MINECO (Spanish Ministry of Economy) through grant ESP2016-80079-C2-1-R and RTI2018-095076-B-C21 (MINECO/FEDER, UE), and MDM-2014-0369 of ICCUB (Unidad de Excelencia ‘María de Maeztu’). AM acknowledges support from the State Research Agency (AEI) of the Spanish Ministry of Science, Innovation and Universities (MCIU) and the European Regional Development Fund (FEDER) under grant AYA2017-83383-P. PJG is partially supported by NRF-SARChI grant 111692 and acknowledges support from the Netherlands Organisation for Scientific Research (NWO), in contributing to the Isaac Newton Group of Telescopes and through grant 614.000.601. Aspects of the analysis presented have been carried out via TOPCAT and STILTS (Taylor 2006). This research has made use of both the SIMBAD database and the “Aladin sky atlas”, respectively operated and developed at CDS, Strasbourg, France. This research has also made use of the image manipulation software, MONTAGE. It is funded by the National Science Foundation under Grant Number ACI-1440620, and was previously funded by the National Aeronautics and Space Administration’s Earth Science Technology Office, Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the California Institute of Technology.

We present the analysis of XMM–Newton European Photon Imaging Camera (EPIC) observations of the nova shell IPHASX J210204.7+471015. We detect X-ray emission from the progenitor binary star with properties that resemble those of underluminous intermediate polars such as DQ Herculis (DQ Her): an X-ray-emitting plasma with temperature of TX = (6.4 ± 3.1) × 106 K, a non-thermal X-ray component, and an estimated X-ray luminosity of LX = 1030 erg s−1. Time series analyses unveil the presence of two periods, the dominant with a period of 2.9 ± 0.2 h, which might be attributed to the spin of the white dwarf, and a secondary of 4.5 ± 0.6 h that is in line with the orbital period of the binary system derived from optical observations. We do not detect extended X-ray emission as in other nova shells probably due to its relatively old age (130–170 yr) or to its asymmetric disrupted morphology that is suggestive of explosion scenarios different to the symmetric ones assumed in available numerical simulations of nova explosions. © 2021 The Author(s)., The authors thank the referee for a prompt report. JAT acknowledges support from the Fundación Marcos Moshinsky (Mexico). JAT is funded by PAPIIT project IA100720 of the Direccion General de Asuntos del Personal Academico of the Universidad Nacional Autonoma de México (DGAPA, UNAM). ES and GR are thankful to Consejo Nacional de Ciencia y Tecnología (CONACyT -México) for their student grants. MAG acknowledges support of the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU) grant PGC2018-102184-B-I00 and 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). GR-L acknowledges support from CONACYT grant 263373. LS acknowledges support from PAPIIT-UNAM grant IN101819. This work has made extensive use of NASA's Astrophysics Data System (ADS).

A correction has been published: Monthly Notices of the Royal Astronomical Society, Volume 509, Issue 2, January 2022, Page 2896, https://doi.org/10.1093/mnras/stab3247, We present a comprehensive analysis of the compact planetary nebula M 2-31 investigating its spectral properties, spatio-kinematical structure, and chemical composition using Gran Telescopio Canarias (GTC) Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía (MEGARA) integral field spectroscopic observations and Nordic Optical Telescope(NOT) Alhambra Faint Object Spectrograph and Camera (ALFOSC) medium-resolution spectra and narrow-band images. The GTC MEGARA high-dispersion observations have remarkable tomographic capabilities, producing an unprecedented view of the morphology and kinematics of M 2-31 that discloses a fast spectroscopic bipolar outflow along position angles 50° and 230°, an extended shell, and a toroidal structure or waist surrounding the central star perpendicularly aligned with the fast outflows. These observations also show that the C ii emission is confined in the central region and enclosed by the [N ii] emission. This is the first time that the spatial segregation revealed by a two-dimensional map of the C ii line implies the presence of multiple plasma components. The deep NOT ALFOSC observations allowed us to detect broad Wolf-Rayet (WR) features from the central star of M 2-31, including previously undetected broad O vi lines that suggest a reclassification as a [WO4]-type star. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society., JSRG and VMAGG acknowledge support from the Programas de Beca Posdoctorales funded by Dirección General de Asuntos del Personal Académico of the Universidad Nacional Autónoma de México (DGAPA, UNAM). JAT acknowledges funding by DGAPA, UNAM PAPIIT project IA100720 and the Marcos Moshinsky Foundation (Mexico). SC and MAG acknowledge financial support from 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). MAG acknowledges support of the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU) grant PGC2018-102184-B-100. LS acknowledges support from PAPIIT-UNAM grant IN101819. GR-L acknowledges support from CONACYT (grant 263373) and PRODEP (Mexico). The GTC Science Operations group is recognized for scheduling the GTC MEGARA observations beneath the exacting conditions requested by this program.

We thank the anonymous referee for their corrections and help in improving the paper. We warmly thank the entire technical staff of the Observatorio Astronomico Nacional at San Pedro Martir in Mexico for their unfailing support to SAINT-EX operations, namely: E. Cadena, T. Calvario, E. Colorado, B. Garcia, G. Guisa, A. Franco, L. Figueroa, B. Hernandez, J. Herrera, E. Lopez, E. Lugo, B. Martinez, J. M. Nunez, J. L. Ochoa, M. Pereyra, F. Quiroz, T. Verdugo, I. Zavala. B.V.R. thanks the Heising-Simons Foundation for support. Y.G.M.C acknowledges support from UNAM-PAPIIT IG-101321. B.-O. D. acknowledges support from the Swiss National Science Foundation (PP00P2-163967 and PP00P2-190080). R.B. acknowledges the support from the Swiss National Science Foundation under grant P2BEP2_195285. M.N.G. acknowledges support from MIT's Kavli Institute as a Juan Carlos Torres Fellow. A.H.M.J.T acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement nffi 803193/BEBOP), from the MERAC foundation, and from the Science and Technology Facilities Council (STFC; grant nffi ST/S00193X/1). T.D. acknowledges support from MIT's Kavli Institute as a Kavli postdoctoral fellow Part of this work received support from the National Centre for Competence in Research PlanetS, supported by the Swiss National Science Foundation (SNSF). The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Fundation (SNF). M.G. and E.J. are F.R.S.-FNRS Senior Research Associate. This publication benefits from the support of the French Community of Belgium in the context of the FRIA Doctoral Grant awarded to MT. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. We acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. Funding for the TESS mission is provided by NASA's Science Mission Directorate. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This paper includes data collected by the TESS mission that are publicly available from the Mikulski Archive for Space Telescopes (MAST). We thank the TESS GI program G03274 PI, Ryan Cloutier, for proposing the target of this work for 2-min-cadence observations in Sector 30. This work is based upon observations carried out at the Observatorio Astronomico Nacional on the Sierra de San Pedro Martir (OAN-SPM), Baja California, Mexico. This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF. This work includes data collected at the Vatican Advanced Technology Telescope (VATT) on Mt. Graham. This paper includes data taken on the EDEN telescope network. We acknowledge support from the Earths in Other Solar Systems Project (EOS) and Alien Earths (grant numbers NNX15AD94G and 80NSSC21K0593), sponsored by NASA. Some of the observations in the paper made use of the High-Resolution Imaging instrument Zorro (Gemini program GS-2020B-LP-105). Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini South telescope of the international Gemini Observatory, a program of NSF's OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigacion y Desarrollo (Chile), Ministerio de Ciencia, Tecnologia e Innovacion (Argentina), Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This work made use of the following Python packages: astropy (Astropy Collaboration 2013, 2018), lightkurve (Lightkurve Collaboration 2018), matplotlib (Hunter 2007), pandas (Wes McKinney 2010), seaborn (Waskom & The Seaborn Development team 2021), scipy (Virtanen et al. 2020) and numpy (Harris et al. 2020)., Context. Large sub-Neptunes are uncommon around the coolest stars in the Galaxy and are rarer still around those that are metal-poor. However, owing to the large planet-to-star radius ratio, these planets are highly suitable for atmospheric study via transmission spectroscopy in the infrared, such as with JWST. Aims. Here we report the discovery and validation of a sub-Neptune orbiting the thick-disk, mid-M dwarf star TOI-2406. The star's low metallicity and the relatively large size and short period of the planet make TOI-2406 b an unusual outcome of planet formation, and its characterisation provides an important observational constraint for formation models. Methods. We first infer properties of the host star by analysing the star's near-infrared spectrum, spectral energy distribution, and Gaia parallax. We use multi-band photometry to confirm that the transit event is on-target and achromatic, and we statistically validate the TESS signal as a transiting exoplanet. We then determine physical properties of the planet through global transit modelling of the TESS and ground-based time-series data. Results. We determine the host to be a metal-poor M4 V star, located at a distance of 56 pc, with properties T-eff = 3100 +/- 75 K, M-* = 0.162 +/- 0.008M(circle dot), R-* = 0.202 +/- 0.011R(circle dot), and [Fe/H] = -0.38 +/- 0.07, and a member of the thick disk. The planet is a relatively large sub-Neptune for the M-dwarf planet population, with R-p = 2.94 +/- 0.17R(circle plus) and P= 3.077 d, producing transits of 2% depth. We note the orbit has a non-zero eccentricity to 3 sigma, prompting questions about the dynamical history of the system. Conclusions. This system is an interesting outcome of planet formation and presents a benchmark for large-planet formation around metal-poor, low-mass stars. The system warrants further study, in particular radial velocity follow-up to determine the planet mass and constrain possible bound companions. Furthermore, TOI-2406 b is a good target for future atmospheric study through transmission spectroscopy. Although the planet's mass remains to be constrained, we estimate the S/N using amass-radius relationship, ranking the system fifth in the population of large sub-Neptunes, with TOI-2406 b having a much lower equilibrium temperature than other spectroscopically accessible members of this population., Heising-Simons Foundation, Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT), Universidad Nacional Autonoma de Mexico IG-101321, Swiss National Science Foundation (SNSF), European Commission PP00P2-163967 PP00P2-190080 P2BEP2_195285, MIT's Kavli Institute as a Juan Carlos Torres Fellow, European Research Council (ERC) nffi 803193/BEBOP, MERAC foundation, UK Research & Innovation (UKRI), Science & Technology Facilities Council (STFC), Science and Technology Development Fund (STDF) nffi ST/S00193X/1, MIT's Kavli Institute as a Kavli postdoctoral fellow, Australian Research Council, Fonds de la Recherche Scientifique - FNRS FRFC 2.5.594.09.F, French Community of Belgium in the context of the FRIA Doctoral Grant, NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center, NASA's Science Mission Directorate, National Aeronautics and Space Administration under the Exoplanet Exploration Program, TESS GI program G03274, National Science Foundation (NSF), Earths in Other Solar Systems Project (EOS), Alien Earths - NASA NNX15AD94G 80NSSC21K0593, High-Resolution Imaging instrument Zorro (Gemini program) GS-2020B-LP-105, NASA Exoplanet Exploration Program, National Aeronautics & Space Administration (NASA)

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., The INT Photometric Hα Survey (IPHAS) has provided us with a number of new emission-line sources, among which planetary nebulae (PNe) constitute an important fraction. Here we present a detailed analysis of the IPHAS nebula Sab 19 (IPHASX J055242.8+262116) based on radio, infrared, and optical images and intermediate- and high-dispersion long-slit spectra. Sab 19 consists of a roundish 0.10 pc in radius double-shell nebula surrounded by a much larger 2.8 pc in radius external shell with a prominent H-shaped filament. We confirm the nature of the main nebula as a PN whose sub-solar N/O ratio abundances, low ionized mass, peculiar radial velocity, and low-mass central star allow us to catalogue it as a Type III PN. Apparently, the progenitor star of Sab 19 became a PN when crossing the Perseus Arm during a brief visit of a few Myr. The higher N/O ratio and velocity shift ≃ 40 km s-1 of the external shell with respect to the main nebula and its large ionized mass suggest that it is not truly associated with Sab 19, but it is rather dominated by a Strömgren zone in the interstellar medium ionized by the PN central star. © The Author(s) 2020. Published by Oxford University Press on behalf of The Royal Astronomical Society., We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). MAG acknowledges support from the Spanish Government Ministerio de Ciencia, Innovacion y Universidades (MCIU) through grant PGC2018-102184-B-I00, LS acknowledges support from DGAPA, UNAM PAPIIT project IN101819, GR-L acknowledges support from Consejo Nacional de Ciencia y Tecnologia (CONACyT) grant 263373 and Programa para el Desarrollo Profesional (PRODEP) Mexico, and EJA acknowledges support from MCIU grant PGC2018-095049-B-C21. MAG and EJA are supported by the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). This research has made use of the SIMBAD database operated at CDS (Strasbourg, France), the NASA/IPAC Infrared Science Archive, which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology, the NASA's Astrophysics Data System, and NRAO VLA Sky Survey. It has also made use of data obtained as part of the INT Photometric Ha Survey (IPHAS) of the Northern Galactic Plane carried out at the Isaac Newton Telescope (INT), which is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrof ' isica de Canarias. All IPHAS data are processed by the Cambridge Astronomical Survey Unit, at the Institute of Astronomy in Cambridge. Based on observations made with the Nordic Optical Telescope (NOT) and Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. NOT is owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku and the University of Oslo, representing Denmark, Finland and Norway, the University of Iceland and Stockholm University. This work is partly based on data obtained with the instruments ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA, and OSIRIS, built by a Consortium led by the Instituto de Astrofisica de Canarias in collaboration with the Instituto de Astronomia of the Universidad Autonoma de México. OSIRIS was funded by GRANTECAN and the National Plan of Astronomy and Astrophysics of the Spanish Government.

We present the first detailed study of the bipolar planetary nebula (PN) IPHASX J191104.8+060845 (PN G 040.6-01.5) discovered as part of the Isaac Newton Telescope Photometric Hα Survey of the Northern Galactic plane (IPHAS). We present Nordic Optical Telescope narrow-band images to unveil its true morphology. This PN consists of a main cavity with two newly uncovered extended low-surface brightness lobes located towards the NW and SE directions. Using near-IR WISE images we unveiled the presence of a barrel-like structure, which surrounds the main cavity, which would explain the dark lane towards the equatorial regions. We also use Gran Telescopio de Canarias spectra to study the physical properties of this PN. We emphasize the potential of old PNe detected in IPHAS to study the final stages of the evolution of the circumstellar medium around solar-like stars. © 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society, The authors are thankful to the referee for a prompt report that improved the presentation of this paper. JBJ-G and JAT are funded by UNAM DGAPA PAPIIT projects IA100318 and IA100720. JBJ-G and LS are funded by UNAM-PAPIIT grant IN101819. SZ works under the collaboration agreement 'UNAM-TecNM 433103020-30-IX-15'. GR-L acknowledges support from CONACYT grant 263373 and PRODEP (Mexico). MAG acknowledges support from the Spanish Government Ministerio de Ciencia, Innovacion y Universidades through grant PGC2018-102184-B-I00. QAP thanks the Hong Kong Research Grants Council for GRF research support under grants 17326116 and 17300417. We thank the daytime and night support staff at the OAN-SPM for facilitating and helping obtain our observations. This paper makes use of data obtained as part of the INT Photometric Ha Survey of the Northern Galactic Plane (IPHAS) carried out at the Isaac Newton Telescope (INT). The INT is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. All IPHAS data are processed by the Cambridge Astronomical Survey Unit, at the Institute of Astronomy in Cambridge. Based on observations collected at the Observatorio Astronomico Nacional at San Pedro Martir, B.C., Mexico. Based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. Based on observations made with the Gran Telescopio Canarias (GTC), installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

We present a detailed analysis of the new planetary nebula (PN) IPHASX J193718.6+202102 using deep imaging and intermediate- and high-resolution spectroscopy that are interpreted through morpho-kinematic and photoionization modelling. The physical structure of the nebula consists of a fragmented torus and an extremely faint orthogonal bipolar outflow, contrary to the pinched waist PN morphology suggested by its optical image. Our kinematic analysis indicates that the torus is expanding at 25 ± 5 km s-1 and is gradually breaking up. At an estimated distance of 7.1-0.3+0.8 kpc, the corresponding kinematic age of ∼26 000 yr is consistent with a faint and disintegrating PN. The intermediate-resolution spectra reveal an excited PN with chemical abundances typical of Type II PNe. Based on the latter, we also estimate an initial mass for the progenitor in the range 2-3 M⊙ and a central star (CSPN) mass MCSPN ∼0.61 M⊙. The Spitzer MIPS 24 μm emission that closely follows the fragmented torus could be attributed to the emission of [O iv] at 25.9 μm rather than to dust emission. All the results coherently point towards an evolved moderately massive bipolar Type II PN on the brink of dissolving into the interstellar medium. © 2020 The Author(s)., The authors are thankful to the referees for their comments that improved this paper. LS acknowledges support from UNAM DGAPA PAPIIT project IN101819 (Mexico). MAG acknowledges support from grant AYA PGC2018-102184-B-I00 co-funded with FEDER funds. SZ works under the collaboration agreement ‘UNAM-TecNM 43310-3020-30-IX-15’. JAT and MAG are funded by UNAM DGAPA PAPIIT project IA100720. GRL acknowledges support from CONACYT (grant 263373) and PRODEP (Mexico). This work is partially based on observations collected at the Observatorio Astronómico Nacional at San Pedro Mártir, B.C., Mexico and we thank the daytime and night support staff at the OAN-SPM for facilitating and helping obtain our observations. Based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association, and the Gran Telescopio Canarias (GTC), both installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias in La Palma, Spain. This paper makes use of data obtained as part of the INT Photometric H α Survey of the Northern Galactic Plane (IPHAS, www.iphas.org) carried out at the Isaac Newton Telescope (INT). The INT is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. All IPHAS data are processed by the Cambridge Astronomical Survey Unit, at the Institute of Astronomy in Cambridge. The bandmerged DR2 catalogue was assembled at the Centre for Astrophysics Research, University of Hertfordshire, supported by STFC grant ST/J001333/1. The OSN director is acknowledged for awarding observations through a DDT programme and the telescope operator Alfredo Sota for conducting the observations. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. In memoriam of Johannes Andersen, director of the NOT from 2002 to 2013.

We present the analysis of the planetary nebula (PN) NGC 2371 around the [Wolf-Rayet] (WR) star WD 0722+295. Our Isaac Newton Telescope intermediate dispersion spectrograph spectra, in conjunction with archival optical and ultraviolet images, unveil in unprecedented detail the high ionization of NGC 2371. The nebula has an apparent multipolar morphology, with two pairs of lobes protruding from a barrel-like central cavity, a pair of dense low ionization knots misaligned with the symmetry axis embedded within the central cavity, and a high-excitation halo mainly detected in He ii. The abundances from the barrel-like central cavity and dense knots agree with abundance determinations for other PNe with [WR]-type central stars of PNe. We suggest that the densest knots inside NGC 2371 are the oldest structures, remnant of a dense equatorial structure, while the main nebular shell and outer lobes resulted from a latter ejection that ended the stellar evolution. The analysis of position-velocity diagrams produced from our high-quality spectra suggests that NGC 2371 has a bipolar shape with each lobe presenting a double structure protruding from a barrel-like central region. The analysis of the spectra of WD 0722+295 results in similar stellar parameters as previously reported. We corroborate that the spectral subtype corresponds with a [WO1] type. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society., VMAGG, JAT, MAG, and HT are funded by Dirección General de Asuntos del Personal Académico (DGAPA), Universidad Nacional Autónoma de México (UNAM) PAPIIT project IA100318. GRL acknowledges support from Fundación Marcos Moshinsky, Consejo Nacional de Ciencia y Tecnología (CONACYT), and Programa para el Desarrollo Profe-sional Docente (PRODEP) (Mexico). MAG acknowledges support of the Spanish Ministerio de Ciencia, Innovación y Universidades grant PGC2018-102184-B-I00, cofunded by FEDER funds. LS thanks support from UNAM PAPIIT grant IN101819. YDM thanks CONACYT for the research grant CB-A1-S-25070. This work has make extensive use of the NASA’s Astrophysics Data System. This paper also presents data obtained with the MOS camera at the Canada–France–Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. The authors thank E. Santamaría for helping produce the velocity sketch of NGC 2371. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

We present a polarimetric investigation of the protoplanetary nebula Frosty Leo performed with the Submillimeter Array. We were able to detect, in the low continuum level (peak at 14.4 mJy beam$^{-1}$), a marginal polarization at $\sim2.6\sigma$. The molecular line investigation based on the CO $J=3\rightarrow2$ emission shows a peak emission of 68.1 Jy beam$^{-1}$ km s$^{-1}$ and the polarization detection in this CO line is also marginal, with a peak at $\sim3.8\sigma$. In both cases, it was therefore not possible to use the electric vector maps (B-field) to accurately trace the magnetic field (B-field) within the PPN. The spatio-kinematic modelling realised with the different velocity channel maps indicates three main structures: a distorted torus accompanied by a bipolar outflow or jet aligned with its axis and a flattened spherical "cap". The comparison of the CO polarization segments with our model suggests that the polarized emission probably arises in the first two components., Comment: 8 pages, Accepted for publication in Monthly Notices of the Royal Astronomical Society

We present a multiwavelength study of the iconic Bubble Nebula (NGC 7635) and its ionizing star BD+60 degrees 2521 We obtained XMM Newton EPIC X-ray observations to search for. extended X-ray emission as in other similar wind-blown bubbles around massive stars. We also obtained San Pedro Madir spectroscopic observations with. the Manchester Echelle Spectrometer to study the dynamics of the Bubble Nebula. Although our EPIC observations are deep, we do not detect extended X-ray emission from this wind-blown bubble. On the other hand, BD+60 degrees 2522 is a bright X-ray source similar to other 0 stars. We used the stellar atmosphere code PolATR to characterize BD+60 degrees 2522 and found that this star is a young O-type star with stellar wind capable of producing a wirid-blown bubble that in principle could be filled with hot gas. We discussed our findings in line with recent ntirnerical simulations'proposing that the Bubble Nebula has been formed as the result of the fast motion of BD+60 degrees 2522 through the medium. Our kinematic study shows that the Bubble Nebula is composed by a series of nested shells, some showing blister-like structures, but with little signatures of hydrodynamical instabilities that would mix the material producing diffuse X-ray emission as seen in other wind-blown bubbles. Its morphology seems to be merely the result of projection effects of these different shells. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society, This work is based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. The NOT data presented were obtained with ALFOSC and FIES, which are provided by the Instituto de Astroffsica de Andalucfa (IAA-CSIC) under ajoint agreement with the University of Copenhagen and NOTSA. This paper makes use of observations carried out at the Observatorio Astronomico Nacional on the Sierra San Pedro Mdfrtir (OAN-SPM), Baja California, Mexico. We thank the daytime and night support staff at the OAN-SPM for facilitating and helping obtain our observations. JAT, MAG, and HT are funded by UNAM DGAPA PAPIIT projects IA100318 and IA100720. GRL acknowledges support from Fundacion Marcos Moshinsky, CONACyT, and PRODEP (Mexico). MAG acknowledges support of the grants AYA 201457280-P and PGC2018-102184-B-I00 of the Spanish Ministerio de Ciencia, Innovacion y Universidades, cofunded with FEDER funds. LS is supported by Direccion General de Asuntos del Personal Acadmico, Universidad Nacional Autonoma de Mexico project IN101819.

Nova shells can provide important information on their distance, their interactions with circumstellar and interstellar media, and the evolution in morphology of the ejecta. We have obtained narrowband images of a sample of five nova shells, namely DQ Her, FH Ser, T Aur, V476 Cyg, and V533 Her, with ages ranging from 50 to 130 yr. These images have been compared with suitable available archival images to derive their angular expansion rates. We find that all the nova shells in our sample are still in the free expansion phase, which can be expected, as the mass of the ejecta is 7-45 times larger than the mass of the swept-up circumstellar medium. The nova shells will keep expanding freely for time periods up to a few hundred years, reducing their time dispersal into the interstellar medium. © 2020. The American Astronomical Society. All rights reserved., E.S., G.R., and J.A.Q.M. acknowledge support from CONACyT and Universidad de Guadalajara. M.A.G. and E.S. acknowledge financial support by grants AYA 2014-57280-P and PGC 2018-102184-B-I00, cofunded with FEDER funds. M.A.G. acknowledges support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). E.S. acknowledges the hospitality of the IAA during a short-term visit. G.R.L. acknowledges support from CONACyT and PRODEP (Mexico). L.S. acknowledges support from UNAM DGAPA PAPIIT project IN101819. M.A.G. and J.A.T. acknowledge support from the UNAM DGAPA PAPIIT project IA 100318. We appreciate the valuable comments of the referee, Dr Nye Evans. Finally, we thank Alessandro Ederoclite for useful discussions and comments. The data presented here were obtained in part with ALFOSC, and provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. This research made use of IRAF, distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. We acknowledge the use of the ESO Science Archive Facility developed in partnership with the Space Telescope European Coordinating Facility (ST-ECF). We also acknowledge the ING archive, maintained as part of the CASU Astronomical Data Centre at the Institute of Astronomy, Cambridge and finally, the STScI, operated by the Association of Universities for research in Astronomy, Inc., under NASA contract NAS5-26555.

We perform numerical simulations to investigate the stellar wind from interacting binary stars. Our aim is to find analytical formulae describing the outflow structure. In each binary system the more massive star is in the asymptotic giant branch and its wind is driven by a combination of pulsations in the stellar surface layers and radiation pressure on dust, while the less massive star is in the main sequence. Time averages of density and outflow velocity of the stellar wind are calculated and plotted as profiles against distance from the centre of mass and colatitude angle. We find that mass is lost mainly through the outer Lagrangian point L2. The resultant outflow develops into a spiral at low distances from the binary. The outflowing spiral is quickly smoothed out by shocks and becomes an excretion disk at larger distances. This leads to the formation of an outflow structure with an equatorial density excess, which is greater in binaries with smaller orbital separation. The pole-to-equator density ratio reaches a maximum value of $\sim10^5$ at Roche-Lobe Overflow state. We also find that the gas stream leaving L2 does not form a circumbinary ring for stellar mass ratios above 0.78, when radiation pressure on dust is taken into account. Analytical formulae are obtained by curve fitting the 2-dimensional, azimuthally averaged density and outflow velocity profiles. The formulae can be used in future studies to setup the initial outflow structure in hydrodynamic simulations of common-envelope evolution and formation of planetary nebulae., 13 pages, 17 figures, accepted for publication in MNRAS

We present a near-infrared imaging polarimetric study of the pre-planetary nebula: Frosty Leo. The observations were carried out in J, H and K' bands using the new polarimeter POLICAN mounted on the 2.1m telescope of the Guillermo Haro Astrophysical Observatory, Sonora, Mexico. The most prominent result observed in the polarization maps is a large and well defined dusty envelope (35\arcsec\ diameter in H-band). The polarization position angles in the envelope are particularly well ordered and nearly parallel to the equator of the nebula (seen in J and H bands). The nebula presents a known bipolar outflow and the envelope completely wraps around it. Within the bipolar lobes, we find high polarization levels ranging from $60\%$ (J band) to $90\%$ (K' band) and the polarization angles trace a centrosymmetric pattern. We found the remnants of superwind shells at the edges of the bipolar lobes and the duration of this phase is around 600 yrs. The origin of polarization features in the nebula is most likely due to a combination of single and multiple scattering. Our results clearly demonstrate new structures that provide new hints on the evolution of Frosty Leo from its previous asymptotic giant branch phase., Comment: 5 figures, 9 pages, accepted in MNRAS

We report H$\alpha$ filter photometry for 197 northern hemisphere planetary nebulae (PNe) obtained using imaging data from the IPHAS survey. H$\alpha$+[N II] fluxes were measured for 46 confirmed or possible PNe discovered by the IPHAS survey and for 151 previously catalogued PNe that fell within the area of the northern Galactic Plane surveyed by IPHAS. After correcting for [N II] emission admitted by the IPHAS H$\alpha$ filter, the resulting H$\alpha$ fluxes were combined with published radio free-free fluxes and H$\beta$ fluxes, in order to estimate mean optical extinctions to 143 PNe using ratios involving their integrated Balmer line fluxes and their extinction-free radio fluxes. Distances to the PNe were then estimated using three different 3D interstellar dust extinction mapping methods, including the IPHAS-based H-MEAD algorithm of Sale (2014). These methods were used to plot dust extinction versus distance relationships for the lines of sight to the PNe; the intercepts with the derived dust optical extinctions allowed distances to the PNe to be inferred. For 17 of the PNe in our sample reliable Gaia DR2 distances were available and these have been compared with the distances derived using three different extinction mapping algorithms as well as with distances from the nebular radius vs. H$\alpha$ surface brightness relation of Frew et al. (2016). That relation and the H-MEAD extinction mapping algorithm yielded the closest agreement with the Gaia DR2 distances., Comment: Accepted by MNRAS, 13 pages, 3 figures. Author accepted manuscript. Accepted on 04/12/2020. Deposited on 04/12/2020

We present a detailed comparative study of the arcs and fragmented ring-like features in the haloes of the planetary nebulae (PNe) NGC 6543, NGC 7009, and NGC 7027 and the spiral pattern around the carbon star AFGL 3068 using high-quality multi-epoch HST images. This comparison allows us to investigate the connection and possible evolution between the regular patterns surrounding AGB stars and the irregular concentric patterns around PNe. The radial proper motion of these features, ≃15 km s-1, are found to be consistent with the AGB wind and their linear sizes and inter-lapse times (500 - 1900 yr) also agree with those found around AGB stars, suggesting a common origin. We find evidence using radiative-hydrodynamic simulations that regular patterns produced at the end of the AGB phase become highly distorted by their interactions with the expanding PN and the anisotropic illumination and ionization patterns caused by shadow instabilities. These processes will disrupt the regular (mostly spiral) patterns around AGB stars, plausibly becoming the arcs and fragmented rings observed in the haloes of PNe.© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society, The authors acknowledge support from grants AYA 2014-57280- P and PGC2018-102184-B-I00, co-funded with FEDER funds. JAT and MAG are funded by DGAPA, UNAM PAPIIT project IA100318, and LS by DGAPA, UNAM PAPIIT project IN101819. GRL acknowledges support from Fundacion Marcos Moshinsky, ´ Consejo Nacional de Ciencia y Tecnolog´ıa (CONACyT), and Programa para el Desarrollo Profesional Docente (PRODEP) (Mexico). BB acknowledges support from program AR-14563 that was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. This paper is based on observations made with the NASA/ESAHubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA), and the Canadian Astronomy Data Centre (CADC/NRC/CSA). The large scale image of NGC 7009 is based on observations collected at the European Southern Observatory by the MUSE science verification team. This work has made extensive use of the NASA’s Astrophysics Data System.

HuBi 1 has been proposed to be member of the rare class of born-again planetary nebulae (PNe), i.e., its central star experienced a very late thermal pulse and ejected highly processed material at high speeds inside the old hydrogen-rich PN. In this Letter we present GTC MEGARA integral field spectroscopic observations of the innermost regions of HuBi 1 at high spectral resolution ≃16 km s-1 and multi-epoch subarcsecond images obtained ≃12 yr apart. The analysis of these data indicates that the inner regions of HuBi 1 were ejected ≃200 yr ago and expand at velocities ≃300 km s-1, in excellent agreement with the born-again scenario. The unprecedented tomographic capabilities of the GTC MEGARA high-dispersion observations used here reveal that the ejecta in HuBi 1 has a shell-like structure, in contrast to the disrupted disk and jet morphology of the ejecta in other born-again PNe. © 2020. The American Astronomical Society. All rights reserved., J.S.R.G. and V.M.A.G.G. acknowledge support from the Programa de Becas posdoctorales of DGAPA UNAM (Mexico). J.S.R.G., V.M.A.G.G., and J.A.T. are funded by the UNAM DGAPA PAPIIT project IA100720 (Mexico). M.A. G. acknowledges support of the Spanish Ministerio de Ciencia, Innovacion y Universidades (MCIU) grant PGC2018-102184-B-I00. M.A.G., S.C., and L.F.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 Astrofisica de Andalucia (SEV-2017-0709). E.S. and G.R.L. acknowledge support from CONACyT. (grant 263373). L.S. acknowledges support from PAPIIT-UNAM grant IN101819. L.F.M. is partially supported by MCIU grant AYA2017-84390-C2-1-R. J.S.R.G. and V.M.A.G.G. thank INAOE for its hospitality during a training course on reduction and analysis of MEGARA data and the organizers of this course Y. D. Mayya and J. Zaragoza-Cardiel for sharing their expertise with us. The GTC Science Operations team is acknowledged for scheduling the GTC MEGARA observations under the stringent conditions demanded by this program.

We present the first part of an investigation on the planetary nebula (PN) PC 22 that focuseson the use of deep imaging and high-resolution echelle spectroscopy to perform a detailedmorpho-kinematical analysis. PC 22 is revealed to be a multipolar PN emitting predominantlyin [O III] and displaying multiple non-symmetric outflows. Its central region is found to be alsoparticularly inhomogeneous with a series of low-ionization structures (knots) located on thepath of the outflows. The morpho-kinematical model obtained with SHAPE indicates that (i) thede-projected velocities of the outflows are rather large, ≥100 km s, while the central regionhas expansion velocities in the range ∼25 to ∼45 km s following the 'Wilson effect'; (ii) themajority of the measured structures share similar inclination, ≃100°, i.e. they are coplanar;(iii) and all outflows and lobes are coeval (within the uncertainties). All these results make usto suggest that PC 22 is an evolved starfish PN.We propose that the mechanism responsible forthe morphology of PC 22 consists of a wind-shell interaction, where the fast post-asymptoticgiant branch (AGB) wind flows through a filamentary AGB shell with some large voids.© 2017 The Authors., LS acknowledges support from PAPIIT grant IA-101316 (Mexico). GR-L acknowledges support from CONACYT, CGCI, PRODEP and SEP (Mexico). MAG acknowledges support of the grant AYA 201457280-P, co-funded with FEDER funds. SZ acknowledges support from the UNAM-ITE collaboration agreement 1500-479-3-V-04.

Magnetic fields are likely to be an efficient mechanism which can affect evolved intermediate mass stars (i.e. post-AGB stars and planetary nebulae) in different ways such as via the shaping of their envelope. However, observational probes for the presence of those fields are still scarce. I will present a summary of the works, including those from our group, on the detection and measurement of magnetic fields in various evolved objects.

We report the discovery and characterisation of a super-Earth and a sub-Neptune transiting the bright (K = 8:8), quiet, and nearby (37 pc) M3V dwarf TOI-1266. We validate the planetary nature of TOI-1266 b and c using four sectors of TESS photometry and data from the newly-commissioned 1-m SAINT-EX telescope located in San Pedro Mártir (México). We also include additional groundbased follow-up photometry as well as high-resolution spectroscopy and high-angular imaging observations. The inner, larger planet has a radius of R = 2:37+0:16 -0:12 R and an orbital period of 10.9 days. The outer, smaller planet has a radius of R = 1:56+0:15 -0:13 R on an 18.8-day orbit. The data are found to be consistent with circular, co-planar and stable orbits that are weakly influenced by the 2:1 mean motion resonance. Our TTV analysis of the combined dataset enables model-independent constraints on the masses and eccentricities of the planets. We find planetary masses of Mp = 13:5+11:0 -9:0 M (, Embassy of Mexico in Bern, Swiss National Science Foundation (SNSF), Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) Universidad Nacional Autonoma de Mexico IN-107518, DGAPA, Australian Research Council, Fonds de la Recherche Scientifique - FNRS FRFC 2.5.594.09, Swiss National Science Fundation (SNF) - University of Liege, Spanish public funds for research ESP2017-87676-2-2 RYC-2012-09913, Spanish Government, National Aeronautics & Space Administration (NASA), NASA High-End Computing (HEC) Program through the NASA, Baja California, Mexico - Spanish State Research Agency (AEI) MDM-2017-0737, Unidad de Excelencia "Maria de Maeztu"- Centro de Astrobiologia (INTA-CSIC), Junta de Andalucía, European Research Council (ERC) 336480, Alfred P. Sloan Foundation, National Aeronautics & Space Administration (NASA) 80NSSC18K1585 80NSSC19K0379, National Science Foundation (NSF) AST-1717000, Antoine de Saint-Exupery Youth Foundation

The Observatorio Astron´omico Nacional on the Sierra San Pedro M´artir (OAN-SPM) in Baja California, Mexico is currently undergoing a substantial expansion in its observational infrastructure. The OAN-SPM’s three principal telescopes were installed in the 1970s. In 2015, the BOOTES-5 telescope was installed and is now operational (partners: Mexico, Spain, South Korea). In 2011 the construction of the TAOS-II project begun and its three telescopes are now in commissioning (partners: Taiwan, Mexico, USA, Canada). Also undergoing commissioning are the COATLI and DDOTI projects (both: Mexico, USA). Two projects, COLIBR´I and SAINT-EX are about to begin construction (COLIBR´I: Mexico, France; SAINT-EX: Switzerland, Mexico, UK). Finally, the Telescopio San Pedro M´artir project is advancing through its design phase (partners: Mexico, USA). All save the TSPM are fully funded, so the OAN-SPM will host 11-12 telescopes by the 2020’s, ranging in size from 28cm to 6.5m.

Planetary nebulae are ionized clouds of gas formed by the hydrogen-rich envelopes of low- and intermediate-mass stars ejected at late evolutionary stages. The strong UV flux from their central stars causes a highly stratified ionization structure, with species of higher ionization potential closer to the star. Here, we report on the exceptional case of HuBi 1, a double-shell planetary nebula whose inner shell presents emission from low-ionization species close to the star and emission from high-ionization species farther away. Spectral analysis demonstrates that the inner shell of HuBi 1 is excited by shocks, whereas its outer shell is recombining. The anomalous excitation of these shells can be traced to its low-temperature [WC10] central star whose optical brightness has declined continuously by 10 magnitudes in a period of 46 years. Evolutionary models reveal that this star is the descendant of a low-mass star (≃1.1 M) that has experienced a ‘born-again’ event whose ejecta shock-excite the inner shell. HuBi 1 represents the missing link in the formation of metal-rich central stars of planetary nebulae from low-mass progenitors, offering unique insight regarding the future evolution of the born-again Sakurai’s object. Coming from a solar-mass progenitor, HuBi 1 represents a potential end-state for our Sun., Some of the data presented in this article were obtained with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. The Nordic Optical telescope (NOT) is installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma (Spain). This article is also based on observations carried out at the Observatorio Astronomico Nacional on the Sierra San Pedro Martir (OAN SPM), Baja California, Mexico. We thank the daytime and night support staff at the OAN SPM for facilitating and helping obtain our observations. A.A. and C.M. acknowledge support through the CONACyT project CONACyT-CB2015-254132. G.R.-L. acknowledges support from Universidad de Guadalajara, Fundacion Marcos Moshinsky, ProMoFID2018 and CONACyT (grant A1-S-12258). L.S. acknowledges support from PAPIIT grant IA-101316 (Mexico). L.F.M. is supported by Ministerio de Economia, Industria y Competitividad (Spain) grants AYA2014-57369-C3-3 and AYA2017-84390-C2-1-R (cofunded by FEDER funds). M.A.G. acknowledges support of the grant AYA 2014-57280-P, cofunded with FEDER funds. M.M.M.B. is partially supported through ANPCyT grant PICT-2016-0053 and MinCyT-DAAD bilateral cooperation program through grant DA/16/07. S.A.Z. was supported by the ITE-UNAM agreement 1500-479-3-V-04.

With its bright and wide equatorial waist seen almost edge-on ('the butterfly body') and the faint and broad bipolar extensions ('the butterfly wings'), NGC650-1 is the archetypical example of bipolar planetary nebula (PN) with butterfly morphology. We present here deep high-resolution broad- and narrow-band optical images that expose the rich and intricate fine structure of this bipolar PN, with small-scale bubble-like features and collimated outflows. A SHAPE spatio-kinematic model indicates that NGC650-1 has a broad central torus with an inclination angle of 75° with respect to the line of sight,whereas that of the bipolar lobes,which are clearly seen in the position-velocity maps, is 85°. Large field of view deep images show, for first time, an arc-like diffuse envelope in low- and high-excitation emission lines located up to 180 arcsec towards the east-south-east of the central star, well outside the main nebula. This morphological component is confirmed by Spitzer MIPS and WISE infrared imaging, as well as by long-slit low- and high-dispersion optical spectroscopic observations. Hubble Space Telescope images of NGC650-1 obtained at two different epochs ~14 yr apart reveal the proper motion of the central star along this direction. We propose that this motion of the star through the interstellar medium compresses the remnant material of a slow asymptotic giant branch wind, producing this bow-shock-like feature. © 2017 The Author(s)., GRL acknowledges support from Universidad de Guadalajara (Apoyo de Estancias Academicas - RG/003/2017), CONACyT, CGCI, PRODEP, and SEP (Mexico). MAG also acknowledges support of the grant AYA 2011-29754-C03-02 and AYA 2014-57280-P, both co-funded with FEDER funds. LS acknowledges support from PAPIIT grant IA-101316. Based on observations made with the Observatorio Astronomico Nacional at the Sierra de San Pedro Martir, OAN-SPM, which is operated by the Instituto de Astronomia of the Universidad Nacional Autonoma de Mexico. Also based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofisica de Canarias. The data presented here were obtained (in part) with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. This paper is based on observations made with the IAC80 operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. Also based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astroffsica de Canarias, in the island of La Palma. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This work is based (in part) on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. IRAF, the Image Reduction and Analysis Facility, is distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation. XVISTA is an interactive image and spectral reduction and analysis package developed at the Lick Observatory and maintained and distributed by Jon Holtzman at the New Mexico State University at http://ganymede.nmsu.edu/holtz/xvista/.

The morphology and optical spectrum of IPHASX J210204.7+471015, a nebula classified as a possible planetary nebula are, however, strikingly similar to those of AT Cnc, a classical nova shell around a dwarf nova. To investigate its true nature, we have obtained high-resolution narrowband [O iii] and [N ii] images and deep optical spectra. The nebula shows an arc of [N ii]-bright knots notably enriched in nitrogen, while an [O iii]-bright bow shock is progressing throughout the ISM. Diagnostic line ratios indicate that shocks are associated with the arc and bow shock. The central star of this nebula has been identified by its photometric variability. Time-resolved photometric and spectroscopic data of this source reveal a period of 4.26 hr, which is attributed to a binary system. The optical spectrum is notably similar to that of RW Sex, a cataclysmic variable star (CV) of the UX UMa nova-like (NL) type. Based on these results, we propose that IPHASX J210204.7 + 471015 is a classical nova shell observed around a CV-NL system in quiescence.© 2018. The American Astronomical Society. All rights reserved., M.A.G. acknowledges support of the grant AYA 2014-57280-P, cofunded with FEDER funds. L.S. acknowledges support from PAPIIT grant IA-101316 (Mexico). G.T. has been supported by grants PAPIIT IN108316 and CONACyT 166376. G. R.-L. acknowledges support from Universidad de Guadalajara, CONACyT, PRODEP, and SEP (Mexico). AA postdoctoral grant and some computational resources are from CONACyT 2015-CB/254132 and UNAM-DGAPA-PAPIIT-107215 projects. N.J.W. acknowledges an STFC Ernest Rutherford Fellowship. This article is partially based upon observations carried out at the Observatorio Astronomico Nacional on the Sierra San Pedro Martir (OAN SPM), Baja California, Mexico. We thank the daytime and night support staff at the OAN SPM for facilitating and helping obtain our observations. Some of the data presented here were obtained with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. This article is based in part on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. This paper also makes use of data obtained as part of the INT Photometric Ha Survey of the Northern Galactic Plane (IPHAS: http://www.iphas.org) carried out at the Isaac Newton Telescope (INT). The INT is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. All IPHAS data are processed by the Cambridge Astronomical Survey Unit at the Institute of Astronomy in Cambridge. The band-merged DR2 catalog was assembled at the Centre for Astrophysics Research, University of Hertfordshire, supported by STFC grant ST/J001333/1.

The parallax expansion and kinematics of a nova shell can be used to assess its age and distance, and to investigate the interaction of the ejecta with the circumstellar medium. These are key to understand the expansion and dispersal of the nova ejecta in the Galaxy. Multi-epoch images and high-dispersion spectroscopic observations of the recently discovered classical nova shell IPHASX J210204.7 + 471015 around a nova-like system have been used to derive a present-day expansion rate of 0 ''. 100 yr(-1) and an expansion velocity of 285 km s(-1). These data are combined to obtain a distance of 600 pc to the nova. The secular expansion of the nova shell place the event sometime between 1850 and 1890, yet it seems to have been missed at that time. Despite its young age, 130-170 yr, we found indications that the ejecta has already experienced a noticeable deceleration, indicating the interaction of this young nova shell with the surrounding medium.© 2019 The Author(s).Published by Oxford University Press on behalf of the Royal Astronomical Society, ES acknowledges support from Universidad de Guadalajara and Consejo Nacional de Ciencia y Tecnologia (CONACyT). MAG acknowledges support of the grant AYA2014-57280-P, cofunded with Fondo Europeo para el Desarrollo Regional (FEDER) funds. GR-L acknowledges support from Fundacion Marcos Moshinsky, CONACyT, and Programa para el Desarrollo Profesional Docente (PRODEP) (Mexico). LS acknowledges support from Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) grant IA-101316 (Mexico). JAT and MAG are funded by Universidad Nacional Autonoma de Mexico (UNAM), Direccion General de Asuntos del Personal Academico (DGAPA) PAPIIT project IA100318. We thank Martin Henze for his advise on historical records of novae and photographic plates. This paper also makes use of data obtained as part of the INT Photometric H alpha Survey of the Northern Galactic Plane (IPHAS: http://www.iphas.org) carried out at the Isaac Newton Telescope (INT). The INT is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio delRoque de los Muchachos of the Instituto de Astrofisica de Canarias. All IPHAS data are processed by the Cambridge Astronomical Survey Unit at the Institute of Astronomy in Cambridge. The band-merged DR2 catalogue was assembled at the Centre for Astrophysics Research, University of Hertfordshire, supported by STFC grant ST/J001333/1. The Digitized Sky Surveys were produced at the Space Telescope Science Institute (STScI) under US Government grant NAGW-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. The National Geographic Society-Palomar Observatory Sky Atlas (POSS-I) was made by the California Institute of Technology with grants from the National Geographic Society. The second Palomar Observatory Sky Atlas (POSS-II) was made by the California Institute of Technology with funds from the National Science Foundation, the National Geographic Society, the Sloan Foundation, the Samuel Oschin Foundation, and the Eastman Kodak Corporation. The Oschin Schmidt Telescope is operated by the California Institute of Technology and Palomar Observatory. The UK Schmidt Telescope was operated by the Royal Observatory, Edinburgh, with funding from the UK Science and Engineering Research Council (later the UK Particle Physics and Astronomy Research Council), until 1988 June, and thereafter by the Anglo-Australian Observatory. Supplemental funding for sky-survey work at the STScI is provided by the European Southern Observatory. This work made use of the HDAP which was produced at Landessternwarte Heidelberg-Konigstuhl under grant no. 00.071.2005 of the Klaus-Tschira-Foundation.

We have obtained deep narrowband images in the near-infrared H2 (2.122 microns) emission line for a sample of 15 faint Isaac Newton Telescope Photometric Halpha Survey (IPHAS) bipolar planetary nebulae (PNe) to search for molecular material. H2 emission is found in most of them (14 out of 15), mostly associated with rings at their equatorial regions and with their bipolar lobes. These detections add to the high occurrence of H2 emission among bipolar PNe reported in previous works, resulting from the large reservoir of molecular material in these sources and the suitable excitation conditions for H2 emission. The correlation between detailed bipolar morphology and H2 luminosity is also confirmed: bipolar PNe with broad equatorial rings (R-BPNe) have almost no continuum emission, are H2 brighter and have larger H2/Brgamma line ratio than bipolar PNe with pinched equatorial waists (W-BPNe). The origin of this dichotomy is unclear. The larger size and age of R-BPNe are consistent with shock excitation of H2, whereas ultraviolet pumping is most likely the excitation mechanism in the smaller and younger W-BPNe, which would explain their lower H2 luminosity. Although both types of bipolar PNe seem to proceed from the same progenitor population, this does not imply that R-BPNe descend from W-BPNe. Otherwise, we note that some of the H2-weak bipolar PNe harbor post-common envelope binary systems and symbiotic stars. Finally, we suggest that the long-living H2 emission from R-BPNe arises from a discrete distribution of compact knots embedded within the ionized gas at the equatorial region., 13 pages, 9 figures, Accepted for publication in MNRAS

The role of magnetic fields in late type stars, such as Asymptotic Giant Branch stars (AGBs), Post-AGBs and Planetary Nebulae (PNe), is poorly known from an observational point of view. Magnetic fields are however believed to have a non-negligible influence on the dynamics (via mass loss control, outflows shaping) and even on the chemistry (e.g. extra mixing) of these stellar objects. We are therefore presenting two different types of investigation, both based on the use of polarimetry, which aim at filling the gap between the observations on the one hand and the theoretical predictions on the other hand.

We report extensive 3-yr multiwavelength observations of the WZ Sge-type dwarf nova SSS J122221.7-311525 during its unusual double superoutburst, the following decline and in quiescence. The second segment of the superoutburst had a long duration of 33 d and a very gentle decline with a rate of 0.02 mag/d, and it displayed an extended post-outburst decline lasting at least 500 d. Simultaneously with the start of the rapid fading from the superoutburst plateau, the system showed the appearance of a strong near-infrared excess resulting in very red colours, which reached extreme values (B-I~1.4) about 20 d later. The colours then became bluer again, but it took at least 250 d to acquire a stable level. Superhumps were clearly visible in the light curve from our very first time-resolved observations until at least 420 d after the rapid fading from the superoutburst. The spectroscopic and photometric data revealed an orbital period of 109.80 min and a fractional superhump period excess, 24 pages, 19 figures, Matches to MNRAS published version, typos corrected

We investigate a region of the Galactic plane, between 120, 21 pages, 13 figures. Accepted for publication in MNRAS

Context. A lot of effort has been put into the detection and determination of stellar magnetic fields using the spectral signal obtained from the combination of hundreds or thousands of individual lines, an approach known as multi-line techniques. However, so far most of multi-line techniques developed that retrieve stellar mean longitudinal magnetic fields recourse to sometimes heavy simplifications concerning line shapes and Zeeman splittings. Aims. To determine stellar longitudinal magnetic fields by means of the Principal Components Analysis and Zeeman Doppler Imaging (PCA-ZDI) multi-line technique, based on accurate polarised spectral line synthesis. Methods. In this paper we present the methodology to perform inversions of profiles obtained with PCA-ZDI. Results. Inversions with various magnetic geometries, field strengths and rotational velocities show that we can correctly determine the effective longitudinal magnetic field in stars using the PCA-ZDI method., Accepted for publication in Astronomy and Astrophysics

We demonstrate a newly developed mid-infrared planetary nebula (PN) selection technique. It is designed to enable efficient searches for obscured, previously unknown, PN candidates present in the photometric source catalogues of Galactic plane MIR sky surveys. Such selection is now possible via new, sensitive, high-to-medium resolution, MIR satellite surveys such as those from the Spitzer Space Telescope and the all-sky Wide-Field Infrared Survey Explorer (WISE) satellite missions. MIR selection is based on how different colour-colour planes isolate zones (sometimes overlapping) that are predominately occupied by different astrophysical object types. These techniques depend on the reliability of the available MIR source photometry. In this pilot study we concentrate on MIR point source detections and show that it is dangerous to take the MIR GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) photometry from Spitzer for each candidate at face value without examining the actual MIR image data. About half of our selected sources are spurious detections due to the applied source detection algorithms being affected by complex MIR backgrounds and the de-blending of diffraction spikes around bright MIR point sources into point sources themselves. Nevertheless, once this additional visual diagnostic checking is performed, valuable MIR selected PN candidates are uncovered. Four turned out to have faint, compact, optical counterparts in our H-alpha survey data missed in previous optical searches. We confirm all of these as true PNe via our follow-up optical spectroscopy. This lends weight to the veracity of our MIR technique. It demonstrates sufficient robustness that high-confidence samples of new Galactic PN candidates can be extracted from these MIR surveys without confirmatory optical spectroscopy and imaging. This is problematic or impossible when the extinction is large., 14 pages, 7 figures, 7 tables; accepted for publication in MNRAS

We report on the current status of the search for planetary nebulae (PNe) in the IPHAS survey, the 1800 square degree H-alpha survey of the Northern Galactic Plane carried out at La Palma Observatory. The first major installment of the “IPHAS Catalogue of Extended Nebulae” is presented. This includes a complete census of emission-line nebulae in 320 square degrees toward the inner regions of the Galaxy. In this area, more than 450 emission nebulae have been catalogued including 100 known PNe, and 155 new IPHAS candidate PNe.A vigorous programme of spectroscopic confirmation of IPHAS candidate PNe over the entire survey area is underway using a number of telescopes worldwide. So far, around one hundred new PNe over the whole IPHAS area have been spectroscopically confirmed. Their main properties, some outstanding examples, as well as the relevance of the IPHAS survey to determine the total PN population in the Galactic disc and its chemical gradient is discussed.

We report on the discovery of ETHOS 1 (PN G068.1+11.0), the first spectroscopically confirmed planetary nebula (PN) from a survey of the SuperCOSMOS Science Archive for high-latitude PNe. ETHOS 1 stands out as one of the few PNe to have both polar outflows (jets) travelling at $120\pm10$ km/s and a close binary central star. The lightcurve observed with the Mercator telescope reveals an orbital period of 0.535 days and an extremely large amplitude (0.816 mag) due to irradiation of the companion by a very hot pre-white dwarf. ETHOS 1 further strengthens the long suspected link between binary central stars of planetary nebulae (CSPN) and jets. INT IDS and VLT FORS spectroscopy of the CSPN reveals weak N III, C III and C IV emission lines seen in other close binary CSPN and suggests many CSPN with these weak emission lines are misclassified close binaries. We present VLT FORS imaging and Manchester Echelle Spectrometer long slit observations from which a kinematic model of the nebula is built. An unusual combination of bipolar outflows and a spherical nebula conspire to produce an $X$-shaped appearance. The kinematic age of the jets ($1750\pm250$ yrs/kpc) are found to be older than the inner nebula ($900\pm100$ yrs/kpc) consistent with previous studies of similar PNe. Emission line ratios of the jets are found to be consistent with reverse-shock models for fast low-ionisation emitting regions (FLIERS) in PNe. Further large-scale surveys for close binary CSPN will be required to securely establish whether FLIERS are launched by close binaries.

IPHASXJ194359.5+170901 is a new high-excitation planetary nebula with remarkable characteristics. It consists of a knotty ring expanding at a speed of 28 km/s, and a fast collimated outflow in the form of faint lobes and caps along the direction perpendicular to the ring. The expansion speed of the polar caps is 100 km/s, and their kinematical age is twice as large as the age of the ring. Time-resolved photometry of the central star of IPHASXJ194359.5+170901 reveals a sinusoidal modulation with a period of 1.16 days. This is interpreted as evidence for binarity of the central star, the brightness variations being related to the orbital motion of an irradiated companion. This is supported by the spectrum of the central star in the visible range, which appears to be dominated by emission from the irradiated zone, consisting of a warm (6000-7000 K) continuum, narrow C III, C IV, and N III emission lines, and broader lines from a flat H I Balmer sequence in emission. IPHASXJ194359.5+170901 helps to clarify the role of (close) binaries in the formation and shaping of planetary nebulae. The output of the common-envelope evolution of the system is a strongly flattened circumstellar mass deposition, a feature that seems to be distinctive of this kind of binary system. Also, IPHASXJ194359.5+170901 is among the first post-CE PNe for which the existence of a high-velocity polar outflow has been demonstrated. Its kinematical age might indicate that the polar outflow is formed before the common-envelope phase. This points to mass transfer onto the secondary as the origin, but alternative explanations are also considered.

We present the results of the search for candidate Planetary Nebulae interacting with the interstellar medium (PN–ISM) in the framework of the INT Photometric Hα Survey (IPHAS) and located in the right ascension range 18–20 h. The detection capability of this new Northern survey, in terms of depth and imaging resolution, has allowed us to overcome the detection problem generally associated to the low surface brightness inherent to PNe-ISM. We discuss the detection of 21 IPHAS PN–ISM candidates. Thus, different stages of interaction were observed, implying various morphologies i.e. from the unaffected to totally disrupted shapes. The majority of the sources belong to the so-called WZO2 stage which main characteristic is a brightening of the nebula's shell in the direction of motion. The new findings are encouraging as they would be a first step into the reduction of the scarcity of observational data and they would provide new insights into the physical processes occurring in the rather evolved PNe.

We search for very small-diameter galactic planetary nebulae (PNe) representing the earliest phases of PN evolution. A recently published IPHAS catalogue of Ha-emitting stars provides a useful base for this study as all sources present in this catalogue must be of small angular diameter. The PN candidates are selected based on their location in two colour-colour diagrams: IPHAS (r' - Ha) vs. (r' - i'), and 2MASS (J - H) vs. (H - Ks). Spectroscopic follow-up has been carried out on a sample of candidates in order to confirm their nature. We present a total of 83 PN candidates. We were able to obtain spectra or find the classification from the literature for 35 candidates. Five of these objects are likely to be new PNe, including one large bipolar PN discovered serendipitously near an emission-line star. PN distances deduced from extinction-distance relations based on IPHAS field-star photometry are presented for the first time. These yield distance estimates for our objects in the range from 2 kpc to 6 kpc. From the data to hand, we conclude that four of the discovered objects are very probably young PNe., Comment: 18 pages, 15 figures