Suchergebnisse

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. ; Peer reviewed

During its four years of photometric observations, the Kepler space telescope detected thousands of exoplanets and exoplanet candidates. One of Kepler's greatest heritages has been the confirmation and characterization of hundreds of multi-planet systems via transit timing variations (TTVs). However, there are many interesting candidate systems displaying TTVs on such long timescales that the existing Kepler observations are of insufficient length to confirm and characterize them by means of this technique. To continue with Kepler's unique work, we have organized the "Kepler Object of Interest Network" (KOINet), a multi-site network formed of several telescopes located throughout America, Europe, and Asia. The goals of KOINet are to complete the TTV curves of systems where Kepler did not cover the interaction timescales well, to dynamically prove that some candidates are true planets (or not), to dynamically measure the masses and bulk densities of some planets, to find evidence for non-transiting planets in some of the systems, to extend Kepler's baseline adding new data with the main purpose of improving current models of TTVs, and to build a platform that can observe almost anywhere on the northern hemisphere, at almost any time. KOINet has been operational since March 2014. Here we show some promising first results obtained from analyzing seven primary transits of KOI-0410.01, KOI-0525.01, KOI-0760.01, and KOI-0902.01, in addition to the Kepler data acquired during the first and second observing seasons of KOINet. While carefully choosing the targets we set demanding constraints on timing precision (at least 1 min) and photometric precision (as good as one part per thousand) that were achieved by means of our observing strategies and data analysis techniques. For KOI-0410.01, new transit data revealed a turnover of its TTVs. We carried out an in-depth study of the system, which is identified in the NASA Data Validation Report as a false positive. Among others, we investigated a gravitationally bound hierarchical triple star system and a planet-star system. While the simultaneous transit fitting of ground- andspace-based data allowed for a planet solution, we could not fully reject the three-star scenario. New data, already scheduled in the upcoming 2018 observing season, will set tighter constraints on the nature of the system. © ESO 2018. ; Russian Science Foundation, RSF: 14-50-00043 ; LAT-08/2016, 2014-0707 ; Russian Foundation for Basic Research, RFBR: 17-02-00542 ; Lietuvos Mokslo Taryba ; Deutsche Forschungsgemeinschaft, DFG ; Norges ForskningsrÃ¥d: 188910 ; National Science Foundation, NSF: AST-1615315 ; Deutsche Forschungsgemeinschaft, DFG: DR 281/30-1 ; Science and Technology Facilities Council, STFC ; European Regional Development Fund, FEDER: ESP2016-80435-C2-1-R ; European Commission, EC ; NNH05ZDA001C ; Danmarks Grundforskningsfond, DNRF: DNRF106 ; Education, Audiovisual and Culture Executive Agency, EACEA ; Ministério da Educação e Ciência, MEC ; National Aeronautics and Space Administration, NASA: NNX13A124G, NNX13AF62G ; Science and Technology Facilities Council, STFC: ST/P000312/1, ESP2015-65712-C5-4-R ; Ministerio de Economía y Competitividad, MINECO ; Acknowledgements. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant DNRF106). 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. E.A. acknowledges support from NASA Grants NNX13A124G, NNX13AF62G; from National Science Foundation (NSF) grant AST-1615315; and from the NASA Astrobiology Institutes Virtual Planetary Laboratory, supported by NASA under cooperative agreement NNH05ZDA001C. S.W. acknowledges support from the Research Council of Norway grant 188910 to finance service observing at the NOT, and support for International Team 265 (Magnetic Activity of M-type Dwarf Stars and the Influence on Habitable Extra-solar Planets) funded by the International Space Science Institute (ISSI) in Bern, Switzerland. J.F. acknowledges funding from the German Research Foundation (DFG) through grant DR 281/30-1. 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 Astrofísica de Canarias. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de Astrofísica de Andalucía (IAA) under a joint agreement with the University of Copenhagen and NOTSA. Based on observations obtained with the Apache Point Observatory 3.5-m telescope, which is owned and operated by the Astrophysical Research Consortium. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC). This work was supported in part by the Ministry of Education and Science (the basic part of the State assignment, RK no. AAAA-A17-117030310283-7) and by Act no. 211 of the Government of the Russian Federation, agreement no. 02.A03.21.0006. E.H. and I.R. acknowledge support by the Spanish Ministry of Economy and Competitiveness (MINECO) and the Fondo Europeo de Desarrollo Regional (FEDER) through grant ESP2016-80435-C2-1-R, as well as the support of the Generalitat de Catalunya/CERCA programme. E.P., G.T., and Š.M. acknowledge support from the Research Council of Lithuania (LMT) through grant LAT-08/2016. C.D.C. is supported by the Erasmus Mundus Joint Doctorate Program by grant number 2014-0707 from the EACEA of the European Commission. S.E. acknowledges support by the Russian Science Foundation grant No. 14-50-00043 for conducting photometric observations of exoplanets of Kepler's mission. S.I. acknowledges Russian Foundation for Basic Research (project No. 17-02-00542) for support in the processing of the observations. K.P. acknowledges support from the UK Science and Technology Facilities Council through STFC grant ST/P000312/1. H.J.D. acknowledges support by grant ESP2015-65712-C5-4-R of the Spanish Secretary of State for R&D&i (MINECO). KOINet thanks the telescope operators for their invaluable help during some of the observing campaigns at the IAC80 telescope. The IAC80 telescope is operated on the island of Tenerife by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide. C.v.E. is grateful for the invaluable help and contribution of all the telescope operators involved in this work. Eric Agol acknowledges support from a Guggenheim Fellowship.

Facilities: Liverpool:2 m, FTN, OO:0.65, MLO:1 m, BAT, OAO:0.5 m, Swift, Mayall. Software: IRAF (v2.16.1; Tody 1993), Starlink (v2015B; Disney & Wallace 1982), APHOT (Pravec et al. 1994), HEASOFT (v6.16), XIMAGE (v4.5.1), XSPEC (v12.8.2; Arnaud 1996), XSELECT (v2.4c), R (R Development Core Team 2011). ; The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption 10 times, including yearly eruptions from 2008 to 2014. With a measured recurrence period of Prec = 351 ± 13 days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations of the 2013 and 2014 eruptions, we initiated a campaign to ensure early detection of the predicted 2015 eruption, which triggered ambitious ground- and space-based follow-up programs. In this paper we present the 2015 detection, visible to near-infrared photometry and visible spectroscopy, and ultraviolet and X-ray observations from the Swift observatory. The LCOGT 2 m (Hawaii) discovered the 2015 eruption, estimated to have commenced at August 28.28 ± 0.12 UT. The 2013–2015 eruptions are remarkably similar at all wavelengths. New early spectroscopic observations reveal short-lived emission from material with velocities ∼13,000 km s^−1, possibly collimated outflows. Photometric and spectroscopic observations of the eruption provide strong evidence supporting a red giant donor. An apparently stochastic variability during the early supersoft X-ray phase was comparable in amplitude and duration to past eruptions, but the 2013 and 2015 eruptions show evidence of a brief flux dip during this phase. The multi-eruption Swift/XRT spectra show tentative evidence of high-ionization emission lines above a high-temperature continuum. Following Henze et al. (2015a), the updated recurrence period based on all known eruptions is Prec = 174 ± 10 days, and we expect the next eruption of M31N 2008-12a to occur around 2016 mid-September. ; A.F.V., and V.P.G. acknowledge support from RFBR Grant No. 16 February 00758. J.F., J.J., and G.S. acknowledge support from Spanish Ministry of Economy and Competitiveness (MINECO) grant AYA2014-59084-P, the E.U. FEDER funds, and AGAUR/Generalitat de Catalunya grant SGR0038/2014. S.F. acknowledges support from the Russian Scientific Foundation (grant N 14-50-00043) and the Russian Government Program of Competitive Growth of Kazan Federal University. M. Henze acknowledges the support of the Spanish MINECO under grant FDPI-2013-16933. M. Hernanz acknowledges MINECO support under grant ESP2014-56003-R.K.H. was supported by the project RVO:67985815. J.P.O. and K.L.P. acknowledge funding from the UK Space Agency. VARMR acknowledges financial support from the Radboud Excellence Initiative. S.C.W. acknowledges a visiting research fellowship at LJMU. This work has been supported in part by NSF grant AST-1009566 and NASA grant HST-Go-14125.012. ; Peer-reviewed ; Post-print