Letters

  • 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
  • Letter |

    M dwarfs harbour stellar dynamos driven by convective motions in their interiors. Previously, the magnetic field strengths generated by these dynamos were thought to saturate at 4 kG, but this limit has now been busted by four stars with dipole dynamo states.

    • D. Shulyak
    • , A. Reiners
    • , A. Engeln
    • , L. Malo
    • , R. Yadav
    • , J. Morin
    •  & O. Kochukhov
  • Letter |

    Venus Express wind measurements at Venus’s cloud top during the night show a different picture than dayside. Both fast and slow motions are detected (there are only fast ones during the day) as well as many stationary waves related to surface relief.

    • J. Peralta
    • , R. Hueso
    • , A. Sánchez-Lavega
    • , Y. J. Lee
    • , A. García Muñoz
    • , T. Kouyama
    • , H. Sagawa
    • , T. M. Sato
    • , G. Piccioni
    • , S. Tellmann
    • , T. Imamura
    •  & T. Satoh
  • Letter |

    Some star clusters in the Large Magellanic Cloud have extended main-sequence turnoffs, suggesting that the component stars have different ages. However, if the blue main-sequence stars were initially spinning rapidly, and experienced braking, the apparent age difference disappears.

    • Francesca D’Antona
    • , Antonino P. Milone
    • , Marco Tailo
    • , Paolo Ventura
    • , Enrico Vesperini
    •  & Marcella Di Criscienzo
  • Letter |

    Most of the Mars Trojans — asteroids co-orbiting the planet — are dynamically related; thus, they have a common origin. Joint information from spectral observations and dynamical modelling suggests that they were ejected from Mars itself after an impact.

    • D. Polishook
    • , S. A. Jacobson
    • , A. Morbidelli
    •  & O. Aharonson
  • Letter |

    Multiple stars are thought to form either through disk fragmentation or turbulent fragmentation, but the latter has had no clear observational confirmation. Here the authors report misaligned disks around a wide-binary pair, a sign of turbulent fragmentation.

    • Jeong-Eun Lee
    • , Seokho Lee
    • , Michael M. Dunham
    • , Ken’ichi Tatematsu
    • , Minho Choi
    • , Edwin A. Bergin
    •  & Neal J. Evans
  • Letter |

    Low-mass black holes that accrete stars from locally dense environments grow over the Hubble time above a minimal mass of 105 solar masses, independently of their initial mass. This explains why there are no convincing cases of intermediate-mass black holes to date.

    • Tal Alexander
    •  & Ben Bar-Or
  • Letter |

    Combining studies of star formation rates with studies of cloud–magnetic field alignment has revealed that magnetic fields are a primary regulator of star formation. Perpendicular alignment inhibits star formation, whereas parallel alignment facilitates it.

    • Hua-bai Li
    • , Hangjin Jiang
    • , Xiaodan Fan
    • , Qilao Gu
    •  & Yapeng Zhang
  • Letter |

    The brightest galaxy in a cluster is known to align with its host filament in the local Universe. Here this correlation is extended to when the Universe was just a third of its current age. With this, the privileged history of brightest cluster galaxies is reinforced.

    • Michael J. West
    • , Roberto De Propris
    • , Malcolm N. Bremer
    •  & Steven Phillipps
  • Letter |

    Using Si18O as a velocity tracer, evidence is reported for a rotating outflow driven by a magneto-centrifugal disk wind launched by a high-mass young stellar object. This rotation is a signature of the removal of angular momentum by an outflow.

    • Tomoya Hirota
    • , Masahiro N. Machida
    • , Yuko Matsushita
    • , Kazuhito Motogi
    • , Naoko Matsumoto
    • , Mi Kyoung Kim
    • , Ross A. Burns
    •  & Mareki Honma
  • Letter |

    Disk winds from the surfaces of protoplanetary disks remove angular momentum from radii outside ~10 au. Lee et al. show that residual angular momentum is removed at radii <10 au via highly collimated jets launched at the 0.05 au scale, enabling accretion.

    • Chin-Fei Lee
    • , Paul. T. P Ho
    • , Zhi-Yun Li
    • , Naomi Hirano
    • , Qizhou Zhang
    •  & Hsien Shang
  • Letter |

    Coevolving millions of cold dark matter particles and neutrinos within one N-body simulation, TianNu, shows that regions of similar dark matter density can have different neutrino densities. These density variations may have an effect on the cosmic structure.

    • Hao-Ran Yu
    • , J.D. Emberson
    • , Derek Inman
    • , Tong-Jie Zhang
    • , Ue-Li Pen
    • , Joachim Harnois-Déraps
    • , Shuo Yuan
    • , Huan-Yu Teng
    • , Hong-Ming Zhu
    • , Xuelei Chen
    • , Zhi-Zhong Xing
    • , Yunfei Du
    • , Lilun Zhang
    • , Yutong Lu
    •  & XiangKe Liao
  • 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