Letters

  • Letter |

    The discovery of the most energetic transient event to date is reported. Its spectroscopic properties and temporal evolution imply it is powered by shock interaction between expanding material and large quantities of surrounding dense matter.

    • E. Kankare
    • , R. Kotak
    • , S. Mattila
    • , P. Lundqvist
    • , M. J. Ward
    • , M. Fraser
    • , A. Lawrence
    • , S. J. Smartt
    • , W. P. S. Meikle
    • , A. Bruce
    • , J. Harmanen
    • , S. J. Hutton
    • , C. Inserra
    • , T. Kangas
    • , A. Pastorello
    • , T. Reynolds
    • , C. Romero-Cañizales
    • , K. W. Smith
    • , S. Valenti
    • , K. C. Chambers
    • , K. W. Hodapp
    • , M. E. Huber
    • , N. Kaiser
    • , R.-P. Kudritzki
    • , E. A. Magnier
    • , J. L. Tonry
    • , R. J. Wainscoat
    •  & C. Waters
  • Letter |

    A galaxy at z ~ 1 is multiply imaged by strong lensing with different spatial resolutions. The properties of the giant stellar clumps within the galaxy depend on the resolution of the images. This observational effect must be considered in galactic models of star formation.

    • Antonio Cava
    • , Daniel Schaerer
    • , Johan Richard
    • , Pablo G. Pérez-González
    • , Miroslava Dessauges-Zavadsky
    • , Lucio Mayer
    •  & Valentina Tamburello
  • Letter |

    Sensitive X-ray polarization measurements of the Crab pulsar by the Indian AstroSat satellite confirm earlier indications of strongly polarized off-pulse emission but also reveal variations in polarization properties within the off-pulse region.

    • S. V. Vadawale
    • , T. Chattopadhyay
    • , N. P. S. Mithun
    • , A. R. Rao
    • , D. Bhattacharya
    • , A. Vibhute
    • , V. B. Bhalerao
    • , G. C. Dewangan
    • , R. Misra
    • , B. Paul
    • , A. Basu
    • , B. C. Joshi
    • , S. Sreekumar
    • , E. Samuel
    • , P. Priya
    • , P. Vinod
    •  & S. Seetha
  • Letter |

    This paper reports the detection of a high-redshift galaxy that may be more representative of ‘normal’ star-forming galaxies formed in the first billion years of the Universe than the extreme starbursts discovered to date.

    • Jorge A. Zavala
    • , Alfredo Montaña
    • , David H. Hughes
    • , Min S. Yun
    • , R. J. Ivison
    • , Elisabetta Valiante
    • , David Wilner
    • , Justin Spilker
    • , Itziar Aretxaga
    • , Stephen Eales
    • , Vladimir Avila-Reese
    • , Miguel Chávez
    • , Asantha Cooray
    • , Helmut Dannerbauer
    • , James S. Dunlop
    • , Loretta Dunne
    • , Arturo I. Gómez-Ruiz
    • , Michał J. Michałowski
    • , Gopal Narayanan
    • , Hooshang Nayyeri
    • , Ivan Oteo
    • , Daniel Rosa González
    • , David Sánchez-Argüelles
    • , F. Peter Schloerb
    • , Stephen Serjeant
    • , Matthew W. L. Smith
    • , Elena Terlevich
    • , Olga Vega
    • , Alan Villalba
    • , Paul van der Werf
    • , Grant W. Wilson
    •  & Milagros Zeballos
  • Letter |

    Tidal forcing within a very porous (unconsolidated) core can generate enough energy to drive all the observed global features of Enceladus. This activity can be sustained up to several billion years.

    • Gaël Choblet
    • , Gabriel Tobie
    • , Christophe Sotin
    • , Marie Běhounková
    • , Ondřej Čadek
    • , Frank Postberg
    •  & Ondřej Souček
  • Letter |

    The authors discover that Jupiter's southern X-ray aurora is concentrated into a hot spot (until now only the north pole was known to have one), which behaves completely differently in brightness and timing pulsation from its northern counterpart.

    • W. R. Dunn
    • , G. Branduardi-Raymont
    • , L. C. Ray
    • , C. M. Jackman
    • , R. P. Kraft
    • , R. F. Elsner
    • , I. J. Rae
    • , Z. Yao
    • , M. F. Vogt
    • , G. H. Jones
    • , G. R. Gladstone
    • , G. S. Orton
    • , J. A. Sinclair
    • , P. G. Ford
    • , G. A. Graham
    • , R. Caro-Carretero
    •  & A. J. Coates
  • Letter |

    The atmosphere of evolved star W Hya has been resolved with ALMA and shown to be shock heated. These observations provide important empirical constraints for the understanding of circumstellar structure, convection, chemistry and pulsation.

    • Wouter Vlemmings
    • , Theo Khouri
    • , Eamon O’Gorman
    • , Elvire De Beck
    • , Elizabeth Humphreys
    • , Boy Lankhaar
    • , Matthias Maercker
    • , Hans Olofsson
    • , Sofia Ramstedt
    • , Daniel Tafoya
    •  & Aki Takigawa
  • Letter |

    Saturn’s proton radiation belts are quite an isolated system and can be used as a laboratory for endogenous impacts on planetary radiation belts. Their evolution over a solar cycle shows variations associated with changes in magnetospheric radial diffusion.

    • P. Kollmann
    • , E. Roussos
    • , A. Kotova
    • , C. Paranicas
    •  & N. Krupp
  • Letter |

    A delay between rapid optical and X-ray flux variations from an accreting black-hole binary is reported together with a brightening radio jet, indicating a characteristic elevation of the radiative jet base of 0.1 light-seconds above the black hole.

    • P. Gandhi
    • , M. Bachetti
    • , V. S. Dhillon
    • , R. P. Fender
    • , L. K. Hardy
    • , F. A. Harrison
    • , S. P. Littlefair
    • , J. Malzac
    • , S. Markoff
    • , T. R. Marsh
    • , K. Mooley
    • , D. Stern
    • , J. A. Tomsick
    • , D. J. Walton
    • , P. Casella
    • , F. Vincentelli
    • , D. Altamirano
    • , J. Casares
    • , C. Ceccobello
    • , P. A. Charles
    • , C. Ferrigno
    • , R. I. Hynes
    • , C. Knigge
    • , E. Kuulkers
    • , M. Pahari
    • , F. Rahoui
    • , D. M. Russell
    •  & A. W. Shaw
  • Letter |

    The 2010–2011 storm that appeared at Saturn’s northern mid-latitudes significantly altered the wind structure and atmospheric temperature even far away from the storm, by disrupting the quasi-periodic atmospheric oscillations at the equator for more than 3 years.

    • Leigh N. Fletcher
    • , Sandrine Guerlet
    • , Glenn S. Orton
    • , Richard G. Cosentino
    • , Thierry Fouchet
    • , Patrick G. J. Irwin
    • , Liming Li
    • , F. Michael Flasar
    • , Nicolas Gorius
    •  & Raúl Morales-Juberías
  • Letter |

    A double neutron star merger gave rise to the gravitational-wave event GW 170817, with counterpart electromagnetic radiation in the optical and gamma-ray spectra. Polarization measurements of the optical emission reveal a lanthanide-rich macronova.

    • S. Covino
    • , K. Wiersema
    • , Y. Z. Fan
    • , K. Toma
    • , A. B. Higgins
    • , A. Melandri
    • , P. D’Avanzo
    • , C. G. Mundell
    • , E. Palazzi
    • , N. R. Tanvir
    • , M. G. Bernardini
    • , M. Branchesi
    • , E. Brocato
    • , S. Campana
    • , S. di Serego Alighieri
    • , D. Götz
    • , J. P. U. Fynbo
    • , W. Gao
    • , A. Gomboc
    • , B. Gompertz
    • , J. Greiner
    • , J. Hjorth
    • , Z. P. Jin
    • , L. Kaper
    • , S. Klose
    • , S. Kobayashi
    • , D. Kopac
    • , C. Kouveliotou
    • , A. J. Levan
    • , J. Mao
    • , D. Malesani
    • , E. Pian
    • , A. Rossi
    • , R. Salvaterra
    • , R. L. C. Starling
    • , I. Steele
    • , G. Tagliaferri
    • , E. Troja
    • , A. J. van der Horst
    •  & R. A. M. J. Wijers
  • Letter |

    Mapping the optical emission of a galaxy cluster to its mass is challenging. Lensing of the cosmic microwave background by massive clusters is used to calibrate the optical richness of clusters to their total baryonic mass at the ten per cent level.

    • James E. Geach
    •  & John A. Peacock
  • Letter |

    The origin of the broad-line emission from type-1 active galactic nuclei is unclear. Calculations of emission lines from dusty clumps that are tidally disrupted by the central black hole suggest that these clumps give rise to the broad-line emission.

    • Jian-Min Wang
    • , Pu Du
    • , Michael S. Brotherton
    • , Chen Hu
    • , Yu-Yang Songsheng
    • , Yan-Rong Li
    • , Yong Shi
    •  & Zhi-Xiang Zhang
  • Letter |

    The authors detect hard X-ray emission produced by plasma heated at ≥10 million kelvin from a quiescent active region of the Sun, providing clear observational evidence of plasma heating by nanoflares, and hinting at their important role in coronal heating.

    • Shin-nosuke Ishikawa
    • , Lindsay Glesener
    • , Säm Krucker
    • , Steven Christe
    • , Juan Camilo Buitrago-Casas
    • , Noriyuki Narukage
    •  & Juliana Vievering
  • Letter |

    The relatively unexplored southwestern region of the Large Magellanic Cloud is host to a massive, embedded star-forming complex that rivals the star-forming efficiency of 30 Doradus. Its most luminous object could be a super star cluster in formation.

    • Bram B. Ochsendorf
    • , Hans Zinnecker
    • , Omnarayani Nayak
    • , John Bally
    • , Margaret Meixner
    • , Olivia C. Jones
    • , Remy Indebetouw
    •  & Mubdi Rahman
  • Letter |

    Chloromethane (CH3Cl) has been observed towards a low-mass protostar and comet 67P, making it the first organohalogen detected in space. The species was previously considered to be a biomarker, but the authors suggest viable alternative abiotic formation routes.

    • Edith C. Fayolle
    • , Karin I. Öberg
    • , Jes K. Jørgensen
    • , Kathrin Altwegg
    • , Hannah Calcutt
    • , Holger S. P. Müller
    • , Martin Rubin
    • , Matthijs H. D. van der Wiel
    • , Per Bjerkeli
    • , Tyler L. Bourke
    • , Audrey Coutens
    • , Ewine F. van Dishoeck
    • , Maria N. Drozdovskaya
    • , Robin T. Garrod
    • , Niels F. W. Ligterink
    • , Magnus V. Persson
    •  & Susanne F. Wampfler
  • Letter |

    Optical pulsations from a millisecond pulsar that had transitioned from a rotationally powered regime to an accretion disk state have been detected. The optical emission is likely to be due to electron synchrotron emission in a rotation-powered magnetosphere.

    • F. Ambrosino
    • , A. Papitto
    • , L. Stella
    • , F. Meddi
    • , P. Cretaro
    • , L. Burderi
    • , T. Di Salvo
    • , G. L. Israel
    • , A. Ghedina
    • , L. Di Fabrizio
    •  & L. Riverol
  • Letter |

    The polarization resulting from electron scattering in a stellar atmosphere has been detected towards the rapidly spinning star Regulus. Deformation of the star from spherical allows this effect to be seen, fulfilling a prediction from around 50 years ago.

    • Daniel V. Cotton
    • , Jeremy Bailey
    • , Ian D. Howarth
    • , Kimberly Bott
    • , Lucyna Kedziora-Chudczer
    • , P. W. Lucas
    •  & J. H. Hough
  • Letter |

    A tight correlation between gamma rays and optical emission in nova ASASSN-16ma indicates that the optical light comes from reprocessed emission from shocks in the ejecta, rather than an energy release near the hot white dwarf, as in the standard model.

    • Kwan-Lok Li
    • , Brian D. Metzger
    • , Laura Chomiuk
    • , Indrek Vurm
    • , Jay Strader
    • , Thomas Finzell
    • , Andrei M. Beloborodov
    • , Thomas Nelson
    • , Benjamin J. Shappee
    • , Christopher S. Kochanek
    • , José L. Prieto
    • , Stella Kafka
    • , Thomas W.-S. Holoien
    • , Todd A. Thompson
    • , Paul J. Luckas
    •  & Hiroshi Itoh
  • Letter |

    Recent observations reveal tension between various cosmological probes. Assuming dark energy to be non-constant, depending on redshift, may relieve this tension. The Dark Energy Spectroscopic Instrument survey will be able to confirm this result.

    • Gong-Bo Zhao
    • , Marco Raveri
    • , Levon Pogosian
    • , Yuting Wang
    • , Robert G. Crittenden
    • , Will J. Handley
    • , Will J. Percival
    • , Florian Beutler
    • , Jonathan Brinkmann
    • , Chia-Hsun Chuang
    • , Antonio J. Cuesta
    • , Daniel J. Eisenstein
    • , Francisco-Shu Kitaura
    • , Kazuya Koyama
    • , Benjamin L’Huillier
    • , Robert C. Nichol
    • , Matthew M. Pieri
    • , Sergio Rodriguez-Torres
    • , Ashley J. Ross
    • , Graziano Rossi
    • , Ariel G. Sánchez
    • , Arman Shafieloo
    • , Jeremy L. Tinker
    • , Rita Tojeiro
    • , Jose A. Vazquez
    •  & Hanyu Zhang
  • Letter |

    The detection and characterization of a large-scale ordered magnetic field through a gravitational lens in a galaxy beyond the local volume allows us to elucidate how such magnetic fields come about, supporting a mean-field dynamo origin.

    • S. A. Mao
    • , C. Carilli
    • , B. M. Gaensler
    • , O. Wucknitz
    • , C. Keeton
    • , A. Basu
    • , R. Beck
    • , P. P. Kronberg
    •  & E. Zweibel
  • Letter |

    Brightness changes of the Sun over timescales from minutes to decades, relevant to Earth’s climate and the detection of exoplanets around Sun-like stars, can be fully and precisely explained by the magnetic field and granulation of the Sun’s surface.

    • A. I. Shapiro
    • , S. K. Solanki
    • , N. A. Krivova
    • , R. H. Cameron
    • , K. L. Yeo
    •  & W. K. Schmutz
  • Letter |

    Diamonds precipitate from methane under the intense pressures of the atmospheres of Neptune and Uranus. Here, a laser shock experiment on a hydrocarbon sample shows that diamonds may require ten times as much pressure to precipitate as was previously thought.

    • D. Kraus
    • , J. Vorberger
    • , A. Pak
    • , N. J. Hartley
    • , L. B. Fletcher
    • , S. Frydrych
    • , E. Galtier
    • , E. J. Gamboa
    • , D. O. Gericke
    • , S. H. Glenzer
    • , E. Granados
    • , M. J. MacDonald
    • , A. J. MacKinnon
    • , E. E. McBride
    • , I. Nam
    • , P. Neumayer
    • , M. Roth
    • , A. M. Saunders
    • , A. K. Schuster
    • , P. Sun
    • , T. van Driel
    • , T. Döppner
    •  & R. W. Falcone