Letters

  • Letter |

    Orbital parameters for the seventh Earth-sized transiting planet around star TRAPPIST-1 are reported, along with an investigation into the complex three-body resonances linking every member of this planetary system.

    • Rodrigo Luger
    • , Marko Sestovic
    • , Ethan Kruse
    • , Simon L. Grimm
    • , Brice-Olivier Demory
    • , Eric Agol
    • , Emeline Bolmont
    • , Daniel Fabrycky
    • , Catarina S. Fernandes
    • , Valérie Van Grootel
    • , Adam Burgasser
    • , Michaël Gillon
    • , James G. Ingalls
    • , Emmanuël Jehin
    • , Sean N. Raymond
    • , Franck Selsis
    • , Amaury H. M. J. Triaud
    • , Thomas Barclay
    • , Geert Barentsen
    • , Steve B. Howell
    • , Laetitia Delrez
    • , Julien de Wit
    • , Daniel Foreman-Mackey
    • , Daniel L. Holdsworth
    • , Jérémy Leconte
    • , Susan Lederer
    • , Martin Turbet
    • , Yaseen Almleaky
    • , Zouhair Benkhaldoun
    • , Pierre Magain
    • , Brett M. Morris
    • , Kevin Heng
    •  & Didier Queloz
  • Letter |

    ALMA observations of TW Hydrae in the 13C18O J = 3–2 molecular line probe the mid-plane of the circumstellar disk where giant planets are expected to form. With other lines, the gas mass distribution, temperature and the gas-to-dust ratio are determined.

    • Ke Zhang
    • , Edwin A. Bergin
    • , Geoffrey A. Blake
    • , L. Ilsedore Cleeves
    •  & Kamber R. Schwarz
  • Letter |

    The detection of a metal-polluted G star in a binary system with an invisible X-ray source offset from the centre of a supernova remnant leads to the suggestion that this was the progenitor pair behind a core-collapse supernova in RCW 86.

    • Vasilii V. Gvaramadze
    • , Norbert Langer
    • , Luca Fossati
    • , Douglas C.-J. Bock
    • , Norberto Castro
    • , Iskren Y. Georgiev
    • , Jochen Greiner
    • , Simon Johnston
    • , Arne Rau
    •  & Thomas M. Tauris
  • Letter |

    The authors put together measurements of ions and neutral atoms from Cassini and the two Voyagers and find that the heliosphere responds quickly (with a lag of 2–3 years) to the solar cycle and that it is bubble-shaped and not tail-shaped, as usually schematized.

    • K. Dialynas
    • , S. M. Krimigis
    • , D. G. Mitchell
    • , R. B. Decker
    •  & E. C. Roelof
  • Letter |

    Cassini’s camera observed Titan from orbit at different angles (0–166°) and found that the planet looks brighter towards the night than at midday. This effect, linked to the scattering properties of Titanian haze, can also be present in exoplanets.

    • A. García Muñoz
    • , P. Lavvas
    •  & R. A. West
  • Letter |

    A faint galaxy has been detected in the very early Universe thanks to deep observations and a massive cluster gravitationally magnifying its emission. One out of only five such galaxies known, this detection constrains how the Universe was reionized.

    • Austin Hoag
    • , Maruša Bradacˇ
    • , Michele Trenti
    • , Tommaso Treu
    • , Kasper B. Schmidt
    • , Kuang-Han Huang
    • , Brian C. Lemaux
    • , Julie He
    • , Stephanie R. Bernard
    • , Louis E. Abramson
    • , Charlotte A. Mason
    • , Takahiro Morishita
    • , Laura Pentericci
    •  & Tim Schrabback
  • Letter |

    The discovery of several Kuiper belt objects (KBOs) with anomalous properties (they are blue-coloured, whereas KBOs of the same type are red, and they are all binaries) gives constraints on formation processes in the outermost region of the Solar System.

    • Wesley C. Fraser
    • , Michele T. Bannister
    • , Rosemary E. Pike
    • , Michael Marsset
    • , Megan E. Schwamb
    • , J. J. Kavelaars
    • , Pedro Lacerda
    • , David Nesvorný
    • , Kathryn Volk
    • , Audrey Delsanti
    • , Susan Benecchi
    • , Matthew J. Lehner
    • , Keith Noll
    • , Brett Gladman
    • , Jean-Marc Petit
    • , Stephen Gwyn
    • , Ying-Tung Chen
    • , Shiang-Yu Wang
    • , Mike Alexandersen
    • , Todd Burdullis
    • , Scott Sheppard
    •  & Chad Trujillo
  • Letter |

    Global-scale Rossby waves develop in planets’ atmospheres and influence their weather. Now, similar waves, driven by magnetism, are unambiguously detected on the Sun. They can possibly help the forecasting of solar activity and related space weather.

    • Scott W. McIntosh
    • , William J. Cramer
    • , Manuel Pichardo Marcano
    •  & Robert J. Leamon
  • Letter |

    Magnetic energy powers explosive flares on the Sun. Now, observations of unprecedented resolution identify the precursors of such flares in the lower solar atmosphere. These findings will help to constrain theoretical models of flare formation.

    • Haimin Wang
    • , Chang Liu
    • , Kwangsu Ahn
    • , Yan Xu
    • , Ju Jing
    • , Na Deng
    • , Nengyi Huang
    • , Rui Liu
    • , Kanya Kusano
    • , Gregory D. Fleishman
    • , Dale E. Gary
    •  & Wenda Cao
  • Letter |

    A bright outburst of activity from the nucleus of comet 67P, observed by Rosetta in July 2015, is traced back to a cliff that partially collapsed at the same time as the outburst, establishing a link between the two events. The collapse has also exposed the fresh ice present under the surface.

    • M. Pajola
    • , S. Höfner
    • , J. B. Vincent
    • , N. Oklay
    • , F. Scholten
    • , F. Preusker
    • , S. Mottola
    • , G. Naletto
    • , S. Fornasier
    • , S. Lowry
    • , C. Feller
    • , P. H. Hasselmann
    • , C. Güttler
    • , C. Tubiana
    • , H. Sierks
    • , C. Barbieri
    • , P. Lamy
    • , R. Rodrigo
    • , D. Koschny
    • , H. Rickman
    • , H. U. Keller
    • , J. Agarwal
    • , M. F. A’Hearn
    • , M. A. Barucci
    • , J.-L. Bertaux
    • , I. Bertini
    • , S. Besse
    • , S. Boudreault
    • , G. Cremonese
    • , V. Da Deppo
    • , B. Davidsson
    • , S. Debei
    • , M. De Cecco
    • , J. Deller
    • , J. D. P. Deshapriya
    • , M. R. El-Maarry
    • , S. Ferrari
    • , F. Ferri
    • , M. Fulle
    • , O. Groussin
    • , P. Gutierrez
    • , M. Hofmann
    • , S. F. Hviid
    • , W.-H. Ip
    • , L. Jorda
    • , J. Knollenberg
    • , G. Kovacs
    • , J. R. Kramm
    • , E. Kührt
    • , M. Küppers
    • , L. M. Lara
    • , Z.-Y. Lin
    • , M. Lazzarin
    • , A. Lucchetti
    • , J. J. Lopez Moreno
    • , F. Marzari
    • , M. Massironi
    • , H. Michalik
    • , L. Penasa
    • , A. Pommerol
    • , E. Simioni
    • , N. Thomas
    • , I. Toth
    •  & E. Baratti
  • Letter |

    The abundance of Be and V isotopes in calcium–aluminium-rich inclusions (CAIs), the oldest solids in the Solar System, shows that CAIs were irradiated by a gradual flux of radiation from solar flares when the Sun was young and more energetic, for a short time (300 yr) and at close distance (≈0.1 au).

    • Paolo A. Sossi
    • , Frédéric Moynier
    • , Marc Chaussidon
    • , Johan Villeneuve
    • , Chizu Kato
    •  & Matthieu Gounelle
  • Letter |

    The key ingredients for a massive cloud of gas to collapse and directly form a black hole without fragmenting and forming stars are a strong ionizing background emission and a closely timed burst of star formation in its vicinity.

    • John A. Regan
    • , Eli Visbal
    • , John H. Wise
    • , Zoltán Haiman
    • , Peter H. Johansson
    •  & Greg L. Bryan
  • Letter |

    Using asteroseismology to measure the spin axes of stars in two old open star clusters, Corsaro et al. find alignment between significant numbers of stars. It is thought that this is an imprint of the original angular momentum of the parent molecular cloud.

    • Enrico Corsaro
    • , Yueh-Ning Lee
    • , Rafael A. García
    • , Patrick Hennebelle
    • , Savita Mathur
    • , Paul G. Beck
    • , Stephane Mathis
    • , Dennis Stello
    •  & Jérôme Bouvier
  • Letter |

    Cassini’s RADAR has surveyed a region close to Enceladus’s ‘tiger stripes’. It finds a temperate subsurface with warm cracks, indicating that the moon’s icy crust is only a few kilometres thick at these points. A dormant crack hints at episodic geological activity.

    • A. Le Gall
    • , C. Leyrat
    • , M. A. Janssen
    • , G. Choblet
    • , G. Tobie
    • , O. Bourgeois
    • , A. Lucas
    • , C. Sotin
    • , C. Howett
    • , R. Kirk
    • , R. D. Lorenz
    • , R. D. West
    • , A. Stolzenbach
    • , M. Massé
    • , A. H. Hayes
    • , L. Bonnefoy
    • , G. Veyssière
    •  & F. Paganelli
  • Letter |

    A magnetohydrodynamic model for outflows around supermassive black holes can also reproduce the X-ray properties of an outflow around a stellar black hole. This indicates that magnetic forces have a universal role to play in driving these winds.

    • Keigo Fukumura
    • , Demosthenes Kazanas
    • , Chris Shrader
    • , Ehud Behar
    • , Francesco Tombesi
    •  & Ioannis Contopoulos
  • Letter |

    A selected group of intermediate-redshift galaxies appear similar to primeval galaxies. Analysing spectra of these nearer analogues for chemical abundances and ionization levels gives an improved understanding of galaxies that are too faint to study well.

    • Ricardo Amorín
    • , Adriano Fontana
    • , Enrique Pérez-Montero
    • , Marco Castellano
    • , Lucia Guaita
    • , Andrea Grazian
    • , Olivier Le Fèvre
    • , Bruno Ribeiro
    • , Daniel Schaerer
    • , Lidia A.M. Tasca
    • , Romain Thomas
    • , Sandro Bardelli
    • , Letizia Cassarà
    • , Paolo Cassata
    • , Andrea Cimatti
    • , Thierry Contini
    • , Stephane de Barros
    • , Bianca Garilli
    • , Mauro Giavalisco
    • , Nimish Hathi
    • , Anton Koekemoer
    • , Vincent Le Brun
    • , Brian C. Lemaux
    • , Dario Maccagni
    • , Laura Pentericci
    • , Janine Pforr
    • , Margherita Talia
    • , Laurence Tresse
    • , Eros Vanzella
    • , Daniela Vergani
    • , Giovanni Zamorani
    • , Elena Zucca
    •  & Emiliano Merlin
  • Letter |

    The authors find that a nearby planetary system has two terrestrial planets that transit in front of their star (from our perspective). Transiting terrestrial planets are sought after, as they can be characterized in detail, including their atmospheres. Having two in the same system is very rare.

    • Michaël Gillon
    • , Brice-Olivier Demory
    • , Valérie Van Grootel
    • , Fatemeh Motalebi
    • , Christophe Lovis
    • , Andrew Collier Cameron
    • , David Charbonneau
    • , David Latham
    • , Emilio Molinari
    • , Francesco A. Pepe
    • , Damien Ségransan
    • , Dimitar Sasselov
    • , Stéphane Udry
    • , Michel Mayor
    • , Giuseppina Micela
    • , Giampaolo Piotto
    •  & Alessandro Sozzetti
  • Letter |

    A binary system containing a ‘polluted’ white dwarf must host a stable, rocky, circumbinary debris disk, argue Farihi and colleagues. Therefore large planetesimal formation, and potentially terrestrial planet formation, must be robust and common in such systems.

    • J. Farihi
    • , S. G. Parsons
    •  & B. T. Gänsicke
  • Letter |

    The roughly spherical outer regions and aspherical inner regions of protoplanetary nebulae — here imaged by ALMA — are explained in terms of an embedded binary system with stars on eccentric orbits.

    • Hyosun Kim
    • , Alfonso Trejo
    • , Sheng-Yuan Liu
    • , Raghvendra Sahai
    • , Ronald E. Taam
    • , Mark R. Morris
    • , Naomi Hirano
    •  & I-Ta Hsieh
  • Letter |

    An uncharacteristically long stellar disruption from a supermassive black hole has been unravelling over the last decade. Spectral information implies very efficient accretion but recent observations hint at a transition to a less extreme accretion mode.

    • Dacheng Lin
    • , James Guillochon
    • , S. Komossa
    • , Enrico Ramirez-Ruiz
    • , Jimmy A. Irwin
    • , W. Peter Maksym
    • , Dirk Grupe
    • , Olivier Godet
    • , Natalie A. Webb
    • , Didier Barret
    • , B. Ashley Zauderer
    • , Pierre-Alain Duc
    • , Eleazar R. Carrasco
    •  & Stephen D. J. Gwyn
  • Letter |

    Isotopic analyses of stardust have yet to single out a specific stellar origin for it. A revision of the proton-capture rate of 17O has helped to identify intermediate mass stars (4–8 solar masses) as the source of a large fraction of meteoritic stardust.

    • M. Lugaro
    • , A. I. Karakas
    • , C. G. Bruno
    • , M. Aliotta
    • , L. R. Nittler
    • , D. Bemmerer
    • , A. Best
    • , A. Boeltzig
    • , C. Broggini
    • , A. Caciolli
    • , F. Cavanna
    • , G. F. Ciani
    • , P. Corvisiero
    • , T. Davinson
    • , R. Depalo
    • , A. Di Leva
    • , Z. Elekes
    • , F. Ferraro
    • , A. Formicola
    • , Zs. Fülöp
    • , G. Gervino
    • , A. Guglielmetti
    • , C. Gustavino
    • , Gy. Gyürky
    • , G. Imbriani
    • , M. Junker
    • , R. Menegazzo
    • , V. Mossa
    • , F. R. Pantaleo
    • , D. Piatti
    • , P. Prati
    • , D. A. Scott
    • , O. Straniero
    • , F. Strieder
    • , T. Szücs
    • , M. P. Takács
    •  & D. Trezzi
  • Letter |

    The authors present evidence that the lunar soil contains oxygen ions from Earth that escape our atmosphere and reach the Moon through the Earth’s magnetospheric wind. The lunar surface possibly contains clues about the history of Earth’s atmosphere.

    • Kentaro Terada
    • , Shoichiro Yokota
    • , Yoshifumi Saito
    • , Naritoshi Kitamura
    • , Kazushi Asamura
    •  & Masaki N. Nishino
  • Letter |

    The presence of a large underdensity, the dipole repeller, is predicted based on a study of the velocity field of our Local Group of galaxies. The combined effects of this super-void and the Shapley concentration control the local cosmic flow.

    • Yehuda Hoffman
    • , Daniel Pomarède
    • , R. Brent Tully
    •  & Hélène M. Courtois