Articles

  • Article |

    Ground-based near-infrared spectra of Uranus detected hydrogen sulfide (H2S) above the main cloud deck (at a pressure of 1.2–3 bar), suggesting that the bulk sulfur/nitrogen ratio in Uranus’s atmosphere exceeds unity and that the clouds are dominated by H2S ice.

    • Patrick G. J. Irwin
    • , Daniel Toledo
    • , Ryan Garland
    • , Nicholas A. Teanby
    • , Leigh N. Fletcher
    • , Glenn A. Orton
    •  & Bruno Bézard
  • Article |

    How does Titan’s thick brownish haze chemically evolve as it is transported from the upper atmosphere observed by Cassini to the lower regions sampled by Huygens? Laboratory vacuum ultraviolet experiments may explain the observed changes in nitrogen chemistry.

    • Nathalie Carrasco
    • , Sarah Tigrine
    • , Lisseth Gavilan
    • , Laurent Nahon
    •  & Murthy S. Gudipati
  • Article |

    An individual star at z = 1.49 is gravitationally lensed and highly magnified by a foreground galaxy cluster. Fluctuations in the star’s emission provide insight on the mass function of intracluster stars, compact objects and the presence of dark-matter subhaloes.

    • Patrick L. Kelly
    • , Jose M. Diego
    • , Steven Rodney
    • , Nick Kaiser
    • , Tom Broadhurst
    • , Adi Zitrin
    • , Tommaso Treu
    • , Pablo G. Pérez-González
    • , Takahiro Morishita
    • , Mathilde Jauzac
    • , Jonatan Selsing
    • , Masamune Oguri
    • , Laurent Pueyo
    • , Timothy W. Ross
    • , Alexei V. Filippenko
    • , Nathan Smith
    • , Jens Hjorth
    • , S. Bradley Cenko
    • , Xin Wang
    • , D. Andrew Howell
    • , Johan Richard
    • , Brenda L. Frye
    • , Saurabh W. Jha
    • , Ryan J. Foley
    • , Colin Norman
    • , Marusa Bradac
    • , Weikang Zheng
    • , Gabriel Brammer
    • , Alberto Molino Benito
    • , Antonio Cava
    • , Lise Christensen
    • , Selma E. de Mink
    • , Or Graur
    • , Claudio Grillo
    • , Ryota Kawamata
    • , Jean-Paul Kneib
    • , Thomas Matheson
    • , Curtis McCully
    • , Mario Nonino
    • , Ismael Pérez-Fournon
    • , Adam G. Riess
    • , Piero Rosati
    • , Kasper Borello Schmidt
    • , Keren Sharon
    •  & Benjamin J. Weiner
  • Article |

    Two unusual transient events, discovered by Hubble behind a strong-lensing galaxy cluster, can be explained as separate eruptions of a luminous blue variable star or a recurrent nova, or as an unrelated pair of stellar microlensing events.

    • S. A. Rodney
    • , I. Balestra
    • , M. Bradac
    • , G. Brammer
    • , T. Broadhurst
    • , G. B. Caminha
    • , G. Chirivì
    • , J. M. Diego
    • , A. V. Filippenko
    • , R. J. Foley
    • , O. Graur
    • , C. Grillo
    • , S. Hemmati
    • , J. Hjorth
    • , A. Hoag
    • , M. Jauzac
    • , S. W. Jha
    • , R. Kawamata
    • , P. L. Kelly
    • , C. McCully
    • , B. Mobasher
    • , A. Molino
    • , M. Oguri
    • , J. Richard
    • , A. G. Riess
    • , P. Rosati
    • , K. B. Schmidt
    • , J. Selsing
    • , K. Sharon
    • , L.-G. Strolger
    • , S. H. Suyu
    • , T. Treu
    • , B. J. Weiner
    • , L. L. R. Williams
    •  & A. Zitrin
  • Article |

    Titan's detached haze, a distinct layer on top of the main haze that provides a measure of the seasonal activity in the mesosphere, disappeared from 2012–2016, after equinox. Studying this transition will help us understand the dynamical and microphysical processes at work.

    • Robert A. West
    • , Benoît Seignovert
    • , Pascal Rannou
    • , Philip Dumont
    • , Elizabeth P. Turtle
    • , Jason Perry
    • , Mou Roy
    •  & Aida Ovanessian
  • Article |

    Laboratory analyses on six carbonaceous chondrites suggest the presence of two water sources with different deuterium (D) enrichment levels in the protoplanetary disk: a D-poor inner reservoir and a D-rich water component transferred inward from the outer disk.

    • Laurette Piani
    • , Hisayoshi Yurimoto
    •  & Laurent Remusat
  • Article |

    Pyrene, a polycyclic aromatic hydrocarbon composed of four fused benzene rings, is putatively a key molecule in the formation of 2D carbonaceous structures. Using experimental and computational techniques, Zhao et al. show that pyrene can form in circumstellar conditions.

    • Long Zhao
    • , Ralf I. Kaiser
    • , Bo Xu
    • , Utuq Ablikim
    • , Musahid Ahmed
    • , Dharati Joshi
    • , Gregory Veber
    • , Felix R. Fischer
    •  & Alexander M. Mebel
  • Article |

    A model for the non-thermal emission of pulsars can fit their γ- and X-ray spectra using just four physical parameters. The model explains several spectral features, and can be used to predict the detectability of pulsars in X-rays given the γ-ray emission, and vice versa.

    • Diego F. Torres
  • Article |

    We calculate the continuous nanohertz gravitational-wave emission from individual supermassive black hole binaries and the gravitational-wave background they generate, which will be observable with pulsar timing arrays.

    • Chiara M. F. Mingarelli
    • , T. Joseph W. Lazio
    • , Alberto Sesana
    • , Jenny E. Greene
    • , Justin A. Ellis
    • , Chung-Pei Ma
    • , Steve Croft
    • , Sarah Burke-Spolaor
    •  & Stephen R. Taylor
  • Article |

    The inner four planets of the TRAPPIST-1 system experienced induction heating due to magnetic interaction with their host star. This led them to experience increased volcanic activity, outgassing and potentially a subsurface magma ocean.

    • K. G. Kislyakova
    • , L. Noack
    • , C. P. Johnstone
    • , V. V. Zaitsev
    • , L. Fossati
    • , H. Lammer
    • , M. L. Khodachenko
    • , P. Odert
    •  & M. Güdel
  • Article |

    Experiments are presented that indicate that methane can be produced abiotically on Mars through the photocatalytic reaction of CO2, in a process called methanogenesis. Methane can then be shocked (through impacts) to form RNA nucleobases and glycine.

    • Svatopluk Civiš
    • , Antonín Knížek
    • , Ondřej Ivanek
    • , Petr Kubelík
    • , Markéta Zukalová
    • , Ladislav Kavan
    •  & Martin Ferus
  • Article |

    By assessing the ionization fraction of the environment around Tycho’s (type Ia) supernova, the authors have constrained the properties of its progenitor enough to rule out a hot, luminous white dwarf. A double white dwarf binary merger is allowed.

    • T. E. Woods
    • , P. Ghavamian
    • , C. Badenes
    •  & M. Gilfanov
  • Article |

    A candidate dual supermassive black hole system with a projected separation of 0.35 pc is found in the gas-rich interacting spiral galaxy NGC 7674, evidenced by a 0.7 kpc Z-shaped radio jet and two, possibly inverted-spectrum, compact radio cores.

    • P. Kharb
    • , D. V. Lal
    •  & D. Merritt
  • Article |

    The authors present a spectrophotometric and hydrodynamical study of supernova OGLE-2014-SN-073, which had remarkably high inferred ejecta mass and energy, potentially higher than can be explained with canonical core-collapse neutrino-driven explosions.

    • G. Terreran
    • , M. L. Pumo
    • , T.-W. Chen
    • , T. J. Moriya
    • , F. Taddia
    • , L. Dessart
    • , L. Zampieri
    • , S. J. Smartt
    • , S. Benetti
    • , C. Inserra
    • , E. Cappellaro
    • , M. Nicholl
    • , M. Fraser
    • , Ł. Wyrzykowski
    • , A. Udalski
    • , D. A. Howell
    • , C. McCully
    • , S. Valenti
    • , G. Dimitriadis
    • , K. Maguire
    • , M. Sullivan
    • , K. W. Smith
    • , O. Yaron
    • , D. R. Young
    • , J. P. Anderson
    • , M. Della Valle
    • , N. Elias-Rosa
    • , A. Gal-Yam
    • , A. Jerkstrand
    • , E. Kankare
    • , A. Pastorello
    • , J. Sollerman
    • , M. Turatto
    • , Z. Kostrzewa-Rutkowska
    • , S. Kozłowski
    • , P. Mróz
    • , M. Pawlak
    • , P. Pietrukowicz
    • , R. Poleski
    • , D. Skowron
    • , J. Skowron
    • , I. Soszyński
    • , M. K. Szymański
    •  & K. Ulaczyk
  • Article |

    A previously unidentified class of variable stars has been found in OGLE survey data, characterized by periodic brightness variations on ~30-min timescales, amplitudes of ~0.3 mag and temperatures of ~30,000 K. They are potentially evolved low-mass stars.

    • Paweł Pietrukowicz
    • , Wojciech A. Dziembowski
    • , Marilyn Latour
    • , Rodolfo Angeloni
    • , Radosław Poleski
    • , Francesco di Mille
    • , Igor Soszyński
    • , Andrzej Udalski
    • , Michał K. Szymański
    • , Łukasz Wyrzykowski
    • , Szymon Kozłowski
    • , Jan Skowron
    • , Dorota Skowron
    • , Przemek Mróz
    • , Michał Pawlak
    •  & Krzysztof Ulaczyk
  • Article |

    Ultrarelativistic photons and neutrinos from gamma-ray bursts offer a testbed for quantum gravity effects that would lead to an energy dependence of the travel times. A statistical analysis of astrophysical data shows that this behaviour may have been observed.

    • Giovanni Amelino-Camelia
    • , Giacomo D’Amico
    • , Giacomo Rosati
    •  & Niccoló Loret
  • Article |

    Using an innovative method, the mass of a pulsar can be constrained using the maximum ‘glitch’ in the star’s rotational frequency: the bigger the glitch, the lower the mass. This method is used to estimate the mass of all observed glitchers.

    • P. M. Pizzochero
    • , M. Antonelli
    • , B. Haskell
    •  & S. Seveso
  • Article |

    The origin of Galactic positrons that produce gamma ray emission when annihilated is still debated. Mergers of two white dwarfs are likely to be the main source of these positrons. Such mergers produce sub-luminous, thermonuclear supernovae.

    • Roland M. Crocker
    • , Ashley J. Ruiter
    • , Ivo R. Seitenzahl
    • , Fiona H. Panther
    • , Stuart Sim
    • , Holger Baumgardt
    • , Anais Möller
    • , David M. Nataf
    • , Lilia Ferrario
    • , J. J. Eldridge
    • , Martin White
    • , Brad E. Tucker
    •  & Felix Aharonian
  • Article |

    The stacking of nearly three-quarters of a million spectra has unearthed a previously unknown component of the Galactic halo: a widely distributed, neutral, excited hydrogen layer that could harbour a sizeable proportion of the Milky Way’s baryons.

    • Huanian Zhang
    •  & Dennis Zaritsky
  • Article |

    Periodic pulsations of polarized emission and a strong magnetic field were found in a white-dwarf double system. These findings confirm a pulsar-like emission mechanism for the system that has so far been associated only with neutron stars.

    • D. A. H. Buckley
    • , P. J. Meintjes
    • , S. B. Potter
    • , T. R. Marsh
    •  & B. T. Gänsicke